Library · Materials, chemistry & fabrication
What Transition Metal Catalysis got wrong, from 80 theses
Summary written by a model from the records below: The records describe various challenges and failure points in transition metal catalysis across homogeneous and heterogeneous systems. Investigators frequently encountered difficulties with catalyst poisoning, ligand incompatibilities, material degradation, poor selectivity, and uncompetitive performance compared to alternative methods. These records come from graduate theses, 2021 to 2026, each labeled with its degree where the repository states it, and each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Plus 10 problems the authors left open, listed at the end.
Failure modes, by theses reporting them
Select a mode to jump to its records.
Catalytic active sites suffer poisoning and deactivation from coordinating substrates or impurities
Catalytic turnover was frequently impeded when coordinating functional groups such as amines, thiols, halides, and diketones bound competitively to transition metal centers. Similar deactivation occurred when reaction solvents, trace moisture, accumulated reaction products, or surface species blocked the active metal sites.
Tried and failed
Suzuki cross-coupling with free thiol functionalised reagents applied to conjugated polymer end-group functionalisation. Outcome: too slow. Reason: Free thiol groups poisoned the palladium catalyst, preventing the cross-coupling reaction from completing
Post-polymerisation modification of conjugated polymers: towards novel organic semiconductor materials · Imperial · PhD
Tried and failed
cationic palladium catalyzed insertion polymerization applied to norbornene derivatives in coordinating ethereal solvents. Outcome: no signal. Reason: coordinating ethereal solvents inhibit or poison the cationic palladium catalyst, preventing polymerization
Chemical Sensing of N-Nitrosodimethylamine and Methane · MIT · PhD
Tried and failed
Late transition metal catalyzed addition polymerization applied to norbornenes with coordinating functional groups. Outcome: no signal. Reason: Coordinating substituents poison or bind competitively to the cationic palladium catalyst, inhibiting polymerization
Chemical Sensing of N-Nitrosodimethylamine and Methane · MIT · PhD
Considered and rejected
Considered and rejected: Rejected synthesis of amide-linked triphenylphosphonium oleanolic acid conjugate via Pd/C hydrogenation of azido intermediate 118 because phosphonium prevented catalyst turnover.
Considered and rejected
Considered and rejected: Rejected Pd2(dba)3 / P(o-tolyl)3 catalyst system in favor of Pd(PPh3)4 because the former was poisoned/inhibited by the pincer ligand side chains.
Dynamic Metal-Ligand Interactions in Semiconducting π-Conjugated Materials · University of Windsor · PhD
Tried and failed
Lewis acid catalyzed epoxide ring opening applied to heterocycle-containing nucleophiles. Reason: Unhindered electron-rich nitrogen heterocycles coordinate competitively to the metal catalyst, causing catalyst poisoning and inhibition
Addressing the Extremes of Reactivity in Small-Molecule-Catalyzed Stereoselective Glycosylation · Harvard · PhD
Tried and failed
Supported nickel catalyst in flow-through reductive fractionation applied to lignocellulosic biomass upgrading. Outcome: unstable. Reason: Rapid catalyst deactivation caused by metal sintering, leaching, and surface poisoning from soluble biomass components
Catalytic Upgrading of Lignin From Biomass · MIT · PhD
Tried and failed
catalytic low-temperature supercritical water gasification applied to sulfur-rich biomass waste. Reason: sulfur compounds rapidly poisoned and deactivated the catalysts
Decision support for the design of integrated biorefineries · EPFL · PhD
Tried and failed
electrochemical decomposition on noble metal catalysts applied to ammonium formate decomposition. Outcome: unstable. Reason: catalyst poisoning and voltage instability over time
Kinetic and Thermodynamic Aspects of Voltage as a Driving Force for Ammonia Activation · MIT · PhD
Tried and failed
ring-opening metathesis polymerisation with ruthenium catalyst applied to functionalised cyclic diketone monomers. Reason: diketone coordination to the ruthenium catalyst poisoned or deactivated the catalyst
Development of additives for the controlled degradation of polyethylene · Imperial · Doctorate
Tried and failed
one-pot catalytic functionalization using in situ reagents applied to diazo compound alkynylation. Reason: catalyst deactivation caused by metal coordination poisoning from reaction components
Novel Alkynylation Methods through the Combination of Hypervalent Iodine Reagents and Alkynyl-trifluoroborate Salts · EPFL · PhD
Tried and failed
anhydrous catalytic oxidation over metal oxide applied to room temperature volatile organic compound oxidation. Reason: absence of water causes catalyst poisoning through intermediate accumulation of formates and carbonates
Trends in C-H bond dehydrogenation energetics for small molecule conversion · MIT · PhD
Considered and rejected
Considered and rejected: Rejected phosphate buffer electrolytes for bicarbonate dependence studies due to catalyst surface poisoning.
Overcoming challenges of fundamental electrochemical kinetic studies under dilute-reagent conditions · MIT · PhD
Considered and rejected
Considered and rejected: Rejected final-step 18F-fluorination on unprotected secondary amine precursors due to catalyst poisoning/inhibition
Copper-mediated radiosynthesis of 18F- and 123I-radiolabelled PARP inhibitors · Oxford · PhD
Considered and rejected
Considered and rejected: Direct debenzylation of secondary amine/conjugate 35 using catalytic transfer hydrogenation or standard Pd/C failed due to amine poisoning of the catalyst, requiring BCl3 with pentamethylbenzene scavenger.
Oligosaccharides based antibacterial drug conjugates · Leibniz Universität Hannover · PhD
Considered and rejected
Considered and rejected: Rejected Pt and Pd catalysts as primary study catalysts because they are too active for ORR (reducing methane activation sites) and suffer CO poisoning upon overoxidation.
ELECTROCHEMICAL CONVERSION OF METHANE TO LIQUID PRODUCTS MEDIATED BY REACTIVE OXYGEN SPECIES · Johns Hopkins · Master's
Considered and rejected
Considered and rejected: Rejected methanol/ethanol recrystallization without drying agents for imine substrates due to trace moisture poisoning the Lewis acid/superbase catalyst.
Organic Superbases in Catalytic Antimony-Carbon Bond Formation and Frustrated Lewis Pair Hydrogenation of Imines. · Texas Tech · PhD
Considered and rejected
Considered and rejected: Platinum group metal catalysts in desalination fuel cells deprioritized due to catalyst poisoning by halide ions in the brine.
Selective Ion Separations Using Shock Electrodialysis · MIT · PhD
Considered and rejected
Considered and rejected: Rejected Karstedt's platinum catalyst for polar bottlebrush polymers containing cyano groups due to catalytic poisoning by nitrogen compounds
Bottlebrush Dielectric Elastomers with Improved Properties for Actuation · EPFL · PhD
Suboptimal ligand selection and precatalyst choices deliver inferior catalytic yields
Specific phosphine, pyridone, or bidentate ligands failed to activate target bonds or initiated competitive side pathways such as retro-aldol cleavages. Across various coupling and isomerization transformations, alternate precatalysts delivered poor conversions and lower yields than established baseline catalyst systems.
Tried and failed
anionic palladium catalysts in cross-coupling applied to heteroaryl reductive cross-coupling. Outcome: no signal. Reason: complexes provided no catalytic improvement over standard palladium precursors
Development of catalytic carbon-carbon bond forming reactions by leveraging the iodide effect · UT Austin · PhD
Tried and failed
electron-deficient pyridone ligands in palladium-catalysed C-H functionalisation applied to palladium norbornene relay C-H acetoxylation. Reason: electron-deficient pyridone ligands deactivated the palladium catalyst giving trace product
Exploring novel strategies for C-H functionalisation of aryl boronates and asymmetric synthesis of functionalised azetidines · Imperial · PhD
Tried and failed
Zero-valent palladium precatalysts applied to Directed catalytic C-H functionalisation. Outcome: worse than baseline. Reason: Lower oxidation state precatalysts failed to improve reaction efficiency compared to standard palladium(II) salts
Tertiary alkylamines as effective directing groups for palladium-catalysed C(sp3)–H activation strategies · Cambridge · PhD
Tried and failed
bidentate chiral phosphines in palladium allylic reduction applied to allylic carbonate hydrogenolysis. Reason: bidentate phosphine ligands resulted in no catalytic conversion
Total synthesis of the acetyl CoA carboxylase allosteric inhibitor soraphen A and the development of new catalytic methods using palladium, iridium and rhodium · UT Austin · PhD
Lost to a baseline
Addition of HSiPh3 to [(μ-dcpe)Pd]2 (forming silyl palladium hydride 6b in situ) impeded the catalytic isomerization of 4-allylanisole compared to [(μ-dcpe)Pd]2 alone.
The Oxidative Addition of Palladium(0) to Hydro- and Halo- Silanes: Mechanisms and Applications · University of Oregon · PhD
Lost to a baseline
Mononuclear PdII complex C22 exhibited notably lower catalytic activity in Heck coupling compared to heterometallic polymers C24-C26
Kompleksy metalosupramolekularne z metalami d-elektronowymi jako wysoce efektywne i selektywne systemy katalityczne Metallosupramolecular complexes with d-block metals as highly effective and selective catalytic systems · Adam Mickiewicz University · PhD
Lost to a baseline
Pd(TFA)2 (26%), PdCl2 (16%), CpPd(allyl) (20%), and Pd2(dba)3 (20%) precatalysts all gave lower yields than Pd(OAc)2 (38%) in desulfinamidative coupling.
Palladium-catalysed desulfinative cross-coupling reactions: Leveraging mechanistic insights for reaction optimisation · Oxford · PhD
Considered and rejected
Considered and rejected: Rejected cross-coupling catalysts RuPhos Pd G4 and rac-BINAP+Pd(OAc)2 in Dad intermediate synthesis due to lower yields compared to BrettPhos Pd G1.
Towards The Development Of Intrinsically Fluorescent Unnatural Amino Acids For In Vivo Incorporation Into Proteins · Penn · PhD
Lost to a baseline
Hov-Grubbs 2nd generation catalyst gave worse yields than slower-initiating indenylidene catalyst M202 in ring expansion optimization.
1, 3-Diene Synthesis, Functionalization and Applications Via Ene-Yne Metathesis and Cobalt Mediated Hydrogen Atom Transfer for the Synthesis Nannocystin A · University at Buffalo · PhD
Considered and rejected
Considered and rejected: Use of second-generation Hoveyda-Grubbs catalyst for cross-metathesis of 2.18 and 2.27 was abandoned in favor of the less hindered and electronically different Nitro-Grela SI-o-tolyl catalyst.
Total synthesis of the acetyl CoA carboxylase allosteric inhibitor soraphen A and the development of new catalytic methods using palladium, iridium and rhodium · UT Austin · PhD
Lost to a baseline
Allylbenzene self-metathesis with Ru1 gave 85:15 E/Z ratio, failing to match Grubbs Z-selective catalyst GIII (11:89 E/Z ratio).
N-Heterocyclic Carbene Containing Macrocycles: Design, Synthesis and Applications · University at Buffalo · PhD
Catalyst instability results in precipitation, leaching, sintering, or destructive decomposition
Active transition metal complexes frequently degraded via premature reduction into metal black, severe leaching, or structural decomplexation during reaction or purification. Operating under harsh thermal, oxidative, or acidic conditions provoked aggressive support etching, substrate destruction, and metallic phase coking.
Tried and failed
heterogeneous palladium black catalyst applied to biaryl cross-coupling reactions. Outcome: unstable. Reason: gave poor reproducibility and inconsistent product yields across runs
Tried and failed
silica-supported palladium catalyzed continuous-flow cross-coupling applied to fluorinated heteroaryl coupling reactions. Outcome: unstable. Reason: In situ generated fluoride byproducts chemically etched and degraded the silica catalyst support
Automated Execution and Optimization of Flow Chemistry on a Robotic Platform with Integrated Analytics · MIT · PhD
Considered and rejected
Considered and rejected: Rejected the palladium-catalysed vinylation route to ene-carbamates via catalyst 4.6 due to poor synthetic reproducibility (biphasic precipitation and decomplexation)
Photochemical Alkynylations with Hypervalent Iodine Reagents · EPFL · PhD
Tried and failed
pulsed co-electrodeposition without coordinating ligands applied to bimetallic catalyst synthesis. Outcome: unstable. Reason: loss of active transition metal ions due to insoluble precipitate formation and uncontrolled oxidation
Selective Electrochemical Nitrate Reduction to Ammonia over Cobalt-based Catalysts · Queen's University · Master's
Tried and failed
using commercial solvent directly without scavenging pretreatment applied to homogeneous palladium catalysis reactions. Outcome: unstable. Reason: trace reducing impurities caused premature reduction and precipitation of active catalyst as metal black
Electrochemical Mechanisms in Thermochemical Catalysis · MIT · PhD
Tried and failed
transition metal dual catalyzed oxidative olefin functionalization applied to unprotected and basic aminoalkenes. Outcome: unstable. Reason: catalyst deactivation and substrate decomposition under oxidative catalytic conditions
Development of palladium catalyzed olefin functionalizations : regiocontrolled synthesis of C–N, C–B, and C–C bonds · UT Austin · PhD
Tried and failed
transition metal doping in perovskite catalyst applied to solid oxide fuel cell anodes. Outcome: unstable. Reason: Dopants reduced to metallic phase under hydrocarbons, causing rapid coking and cell degradation
Development of Novel Electrode and Catalyst Materials for Solid Oxide Electrochemical Cells · Georgia Tech · PhD
Tried and failed
Post-carbonization acid leaching of metal-impregnated carbons applied to transition metal-doped carbon electrocatalysts. Reason: Severe dissolution and loss of poorly coordinated metal dopants during acid purification
Carbon electrode for the oxygen reduction reaction · Imperial · PhD
Considered and rejected
Considered and rejected: Rejected AuCl as a catalyst due to elevated redox potential causing substantial substrate decomposition.
Catalytic Activation of Strained C–C Bonds · Tübingen · PhD
Considered and rejected
Considered and rejected: Rejected bare MXenes as viable NRR catalysts despite favorable overpotentials because Pourbaix and selectivity analyses show they are unstable and poison/favor HER under operating conditions.
Considered and rejected
Considered and rejected: Rejected DTT and TCEP as chemical reductants for disulfide-containing metal catalysts due to preferential metal abstraction over selective disulfide reduction
The development of switchable initiators for rac-Lactide ring-opening polymerisation · Imperial · PhD
Considered and rejected
Considered and rejected: Rejected 500 °C calcination for single-site catalyst synthesis because it caused Cu agglomeration into metallic particles and destroyed ligand framework.
Regulating Molecular Interactions for Electrochemical Energy Conversion and Storage · Johns Hopkins · PhD
Heterogeneous supports and catalyst immobilization cause severe mass transfer limitations and diminished activity
Anchoring homogeneous transition metal catalysts onto solid supports often reduced conversion and turnover rates relative to their unbound homogeneous counterparts. Heterogeneous frameworks and pellet architectures experienced mass transfer constraints, dense ligand passivation, or coordination saturation that restricted access to active sites.
Lost to a baseline
Grafted heterogeneous catalyst 4 gave only 10% yield for allylbenzene isomerization compared to 45% yield from homogeneous Pd(0) dimer 1.
The Oxidative Addition of Palladium(0) to Hydro- and Halo- Silanes: Mechanisms and Applications · University of Oregon · PhD
Tried and failed
unpyrolyzed metal-organic frameworks as heterogeneous catalysts applied to alcohol oxidation and arene hydrogenation. Outcome: no signal. Reason: active metal sites remained coordination-saturated by organic linkers without thermal decomposition
Tried and failed
extraframework metal oxide cluster catalysis applied to Lewis acid transfer hydrogenation reactions. Outcome: worse than baseline. Reason: Metal oxide clusters lacked accessible Lewis acidic coordination and exhibited negligible catalytic activity compared to framework sites
Catalytic implications of confined solvent ensembles within Lewis acid zeolites · MIT · PhD
Tried and failed
unsupported metal oxide electrocatalyst applied to electrochemical nitrogen reduction. Outcome: worse than baseline. Reason: exhibited much higher cell resistance, leading to lower Faradaic efficiency and yield compared to supported catalysts
REALIZING SELECTIVE ELECTROCHEMICAL CO2 AND N2 REDUCTION BY INTERFACIAL ENGINEERING AND RATIONAL CATALYST DESIGN · Johns Hopkins · PhD
Lost to a baseline
Divergent synthesis G0.5-COOMe-Au NCs had lower catalytic activity in 4-NP reduction compared to directly-synthesized G0.5-COOMe-Au NCs due to higher ligand passivation density.
Chemical functionalization and modification of Au clusters · Saskatchewan · Master's
Lost to a baseline
For cis-cyclooctene ROMP, free HG2 catalyst achieved 100% conversion while anchored mSiO2/SiO2-SH catalyst achieved 85% conversion.
Depolymerization and polymerization in confined spaces · Iowa State · Master's
Lost to a baseline
Heterogeneous IrOx-SiO2 catalyzed hydrogenation of mesityl oxide to MIBK at a faster rate than supported pincer catalyst 23-SiO2.
Investigations Of Pincer Iridium Complexes For Glycerol Deoxygenation And For Alkane Dehydrogenation · Penn · PhD
Lost to a baseline
Freestanding pellet catalytic activity remained inferior to conventional thin-film benchmarks (reduced graphene oxide films, modified carbon fiber paper) due to mass transfer limitations in thick pellets.
Carbon electrode for the oxygen reduction reaction · Imperial · PhD
Lost to a baseline
Pt-only three-way catalyst supported on co-precipitated solid solution Ce0.9Zr0.1O2 underperformed core@shell Pt/0.9CeO2@0.1ZrO2 in both degreened (T90 of 205/248/260 °C vs 188/229/240 °C for CO/THC/NOx) and hydrothermally aged states (T90 of 220/262/263 °C vs 207/237/244 °C).
Development of Low-Temperature Oxidation Catalysts for Diesel and Gasoline Vehicles · University at Buffalo · PhD
Lost to a baseline
Phosphine-containing catalysts (Au11 and biicosahedral Au25 on CeO2) achieved <30% CO conversion at 250 °C after 250 °C pretreatment, severely underperforming thiolate-only Au25/CeO2 (100% conversion).
Lost to a baseline
All thermal-diffusion (TD) prepared Sn-doped TiO2 catalysts achieved only ~3.0–3.8% As(III) oxidation, severely underperforming baseline commercial anatase TiO2 (24.7%).
Engineered Sn doped TiO2 bifunctional catalyst for improved hetero-photocatalytic oxidation of arsenite in water · Imperial · PhD
Lost to a baseline
Re/Al2O3 and other Re-based catalysts showed lower steady-state CO2 methanation activity and methane selectivity compared to benchmark Ni/Al2O3 under conventional continuous feed
Development of novel catalysts for e-fuel production · Politecnico di Torino · PhD
Inadequate activation conditions and non-optimal reactant parameters suppress reaction progress
Reactions failed when catalytic mixtures lacked essential Lewis acid promoters, thermal energy, or appropriate alcohol additives needed to cleave metal intermediates. Adjusting metal loadings too high formed inactive oxide clusters, while harsh chemical reduction or insufficient surface coverage degraded catalytic efficiency.
Tried and failed
room-temperature palladium-catalyzed cross-coupling without external heating applied to sterically hindered heteroaryl C-N bond formation. Reason: catalytic system lacked sufficient thermal activation for oxidative addition or transmetalation/reductive elimination
Development of Deactivation-Resistant Catalysts for Pd-Catalyzed C–N Cross-Coupling Reactions · MIT · PhD
Tried and failed
transition metal-catalyzed alpha-alkylation with unactivated alkyl halides applied to aldehydes via enamine intermediates. Outcome: no signal. Reason: unactivated primary alkyl halides failed to couple across diverse palladium catalysts and ligand conditions
Tried and failed
catalytic hydrogen auto-transfer without acidic alcohol additive applied to enantioselective carbonyl allylation. Outcome: worse than baseline. Reason: inefficient protolytic cleavage of the metal alkoxide intermediate led to very low yield
Development of catalytic carbon-carbon bond forming reactions by leveraging the iodide effect · UT Austin · PhD
Tried and failed
increasing metal dopant loading in zeolite catalysts applied to methane catalytic oxidation. Outcome: worse than baseline. Reason: excessive metal loading formed inactive oxide clusters instead of active isolated sites, lowering turnover frequency
Design and Engineering of Carbon Fixing Material Systems · MIT · PhD
Tried and failed
increasing or decreasing Lewis acid catalyst loading applied to heterocycle condensation reaction. Outcome: worse than baseline. Reason: deviations from optimal catalyst concentration reduced product yield
Synthesis of Nitrogen-Containing and Nitrogen-Substituted Aromatic Compounds for Diverse Applications · Georgia Tech · PhD
Tried and failed
transition metal substitution in porous framework catalysts applied to nitrous oxide activation catalysts. Reason: metal-oxo intermediate formation is thermodynamically unfavorable for late and alkaline earth transition metal centers
Tried and failed
reducing base loading or adding water additive applied to transition metal catalyzed allylic alkylation. Reason: failed to improve reaction conversion
Bypassing premetalated reagents in carbon-carbon bond forming reactions : leveraging stereogenic-at-metal complexes and/or nonmetallic reductants · UT Austin · PhD
Tried and failed
chemical reduction without Lewis acid additive applied to transition metal catalyst activation. Reason: reductant failed to reduce the metal complex without Lewis acid activation
New Radical Approaches to C–C Bond Formation in Small Molecules · Cornell · PhD
Tried and failed
Strong reducing agents and non-aqueous solvents during synthesis applied to metal nanocluster catalytic activity. Outcome: worse than baseline. Reason: harsh reduction and organic solvents produced clusters with markedly reduced catalytic activity compared to mild aqueous conditions
Engineering catalytic gold nanoclusters and nanovesicles for detection of disease · Imperial · PhD
Tried and failed
reducing precursor feed ratio in epitaxy applied to ternary nitride thin film growth. Reason: lower ratio reduced catalytic surface coverage, counterintuitively increasing metal accumulation and precipitating secondary metallic phases
Controlling Adatom Kinetics to Overcome Traditional Limitations for III-Nitride Ternary Alloys · Georgia Tech · PhD
Tried and failed
transition metal impregnation on zeolite catalyst applied to olefin skeletal isomerization. Outcome: worse than baseline. Reason: metal modification degraded catalytic performance and alkali exchange eliminated active acid sites needed for conversion
Promoting And Deactivating Effects of Carbonaceous Deposits During Skeletal 1-Butene Isomerization Over Ferrierite · Georgia Tech · PhD
Catalysts exhibit poor chemo-, regio-, or enantioselectivity by promoting unwanted side pathways
Metal catalysts often preferentially engaged unexpected bonds, leading to competitive beta-hydride elimination, cyclobutene isomerization, or excessive substrate over-hydrogenolysis. In asymmetric settings, catalysts suffered from distal coordination or poor facial control, resulting in low enantiomeric excess or product degradation.
Tried and failed
Suzuki-Miyaura cross-coupling applied to substrates containing N-O bonds. Reason: Palladium catalyst inserted into the weak N-O bond rather than the aryl-halide bond
Chain Scissionable Resists Based on Poly(acetal) Motif for Extreme Ultraviolet Lithography · Cornell · PhD
Considered and rejected
Considered and rejected: Direct cross-coupling of secondary benzylic alcohols/ethers bearing β-hydrogens using dppf ligand rejected because dppf caused exclusive β-hydride elimination whose product inhibited catalytic turnover
TRANSITION METAL CATALYZED CROSS-COUPLINGS OF ALKYL SULFONE ELECTROPHILES · Queen's University · PhD
Considered and rejected
Considered and rejected: Abandoned asymmetric intramolecular coupling on achiral propyl-tethered phenols due to distal catalyst coordination yielding 0-13% ee.
Metal-Catalyzed And Photocatalytic Systems For Oxidative Inter- And Intramolecular Phenol Coupling · Penn · PhD
Tried and failed
dual transition metal catalyzed enantioselective hydroalkenylation applied to unactivated vinyl halides. Reason: gave moderate yields but poor enantioselectivity compared to pseudohalide coupling partners
Considered and rejected
Considered and rejected: Rejected precious/noble metal catalysts (Ru, Pd, Pt) due to high cost and preferential selectivity for undesirable decarboxylation/decarbonylation pathways over dehydration.
Novel Catalysts Development for Production of Jet Fuel Range Hydrocarbons from Vegetable Oils · Saskatchewan · PhD
Considered and rejected
Considered and rejected: Rejected using 1,2-dichloroethane or toluene with single Au(I) catalysts due to poor mass balance and partial cyclization diene byproduct formation, pivoting to dual Au(I)/In(III) catalysis.
Dual-biomimetic meroterpenoid syntheses. A study of acetylenic terpenes in polyene cyclizations applied to the synthesis of resorcylate natural products · Imperial · PhD
Tried and failed
mechanocatalytic hydrogenolysis with supported precious metal catalysts applied to lignin model compounds. Reason: catalysts induced extensive over-hydrogenolysis to methane, degrading carbon balance without yielding monomeric aromatics
The Mechanocatalytic Depolymerization of Lignin and Lignin Model Compounds · Georgia Tech · PhD
Lost to a baseline
SD-1:6-Ag:Pd/carbon catalyst lost all semi-hydrogenation selectivity (0% MBE vs 84.7% for monometallic Ag) due to over-hydrogenation to MBA.
DESIGN AND STRUCTURAL CHARACTERIZATION OF MONOMETALLIC AND BIMETALLIC CLUSTERS FOR SELECTIVE HETEROGENEOUS CATALYSIS · Saskatchewan · PhD
Transition metal systems underperform metal-free controls or present unacceptable contamination concerns
Several transition metal catalysts provided lower yields or insignificant enhancements compared to simple catalyst-free baselines or background reaction conditions. Other metal catalysts were deliberately abandoned to avoid difficult separations, toxic metallic residues, or magnetic contamination in downstream materials.
Lost to a baseline
Metal-modified catalysts (Ag-TiO2, Pt-TiO2, Au-TiO2, etc.) showed lower net C1 accumulation rates than unmodified semiconducting nanoparticles (SiC produced 29.5 nmol m^-2 hr^-1 vs Ag-TiO2 at 0.50 nmol m^-2 hr^-1) without hole scavengers.
Design and Engineering of Carbon Fixing Material Systems · MIT · PhD
Lost to a baseline
Catalyst-free hydrophosphinylation of PhN=C=O gave 64% isolated yield of 44a, whereas catalytic reaction with 5 mol% Fe(C6H3-2,6-Mes2)2 gave a lower isolated yield of 60% after ethanol washing
Addition of P-H Bonds to Heterocumulenes · Nottingham · PhD
Lost to a baseline
Catalytic aerobic oxidation of Li[Phmal] using Fe(OTf)2 alone gave comparable yields of oxidized products (16% b, 41% c) relative to the biomimetic Fe/Tbim catalyst (22% b, 41% c)
Adventures in Coordination Chemistry: Biomimetic Fe(II) and Mn(III) Complexes with fac-N,N,N/O Coordination and a Brief Foray into Low Coordinate Organometallic P,N-Fe(II) Complexes · University at Buffalo · PhD
Lost to a baseline
Photocatalytic C–H trifluoromethylation of benzene using CoCl2 in place of III gave a statistically insignificant increase in yield relative to metal-free conditions (37% vs 35%).
Redox non-innocent bis(phenoxide) pincer ligand cobalt complexes for selective radical C–H (trifluoro)alkylation through photoinduced cobalt–R(f) bond weakening · Georgia Tech · PhD
Considered and rejected
Considered and rejected: Abandoned transition-metal-catalyzed directing-group C(sp2)-alkylation on ketones upon finding baseline basic conditions without catalyst promoted direct alpha-C- and O-alkylation.
Considered and rejected
Considered and rejected: Rejected standard dppf iron-catalyzed cyanation protocol, adopting an iron-free dppb catalytic route despite much lower yields to eliminate magnetic contamination in VSM/EPR.
Charge-Transfer States in Organic Nanowires · EPFL · PhD
Lost to a baseline
In situ and ex situ transition metal catalysts resulted in a statistically significant bio-oil yield decrease of nearly 8% compared to the control
Catalytic Upgrading of Biofuel Pyrolysis · Cornell · PhD
Considered and rejected
Considered and rejected: Rejected ring-closing metathesis using Grubbs 2nd generation catalyst due to inability to separate tricyclohexylphosphine oxide and ruthenium impurities without yield loss.
Mechanistic Investigations into Catalytic Wittig Reactions · Nottingham · Master's
Considered and rejected
Considered and rejected: Rejected Grubbs Ru catalyst 2.3 for biological studies due to persistent colored impurities, trace metal chelation, and lower water solubility.
Synthetic Mucins for Microbial Modulation · MIT · PhD
Multimetallic and bimetallic catalyst architectures fail to achieve synergistic performance gains
Combining multiple metals into alloys or multi-atom catalysts often yielded higher degradation rates, elevated overpotentials, and lower activity than pure monometallic benchmarks. Physical mixtures of separate homometallic constituents failed to reproduce the necessary cooperative reactivity observed in integrated complexes.
Lost to a baseline
Monometallic Pt octahedral nanocrystals exhibited significantly lower catalytic activity toward competitive acetylene hydrogenation even at 180 °C compared to Pd octahedra, which achieved complete conversion at 160 °C.
Palladium-Based Nanocrystals with Controlled Surfaces for Catalytic Applications · Georgia Tech · PhD
Lost to a baseline
Monometallic Pt/C showed higher overall catalytic activity (W/F = 0.01-0.3) than bimetallic Pt-M alloys (W/F = 1) for 2-acetylfuran conversion, despite having lower target selectivity.
Metal And Metal Oxide Nanocrystals For Catalysis And Magnetic Applications · Penn
Lost to a baseline
Mixed-metal and Fe-based catalysts (NiFe2O4, NiCoO2, Ni0.5Co0.5Fe2O4) had much higher overpotentials and degradation rates than baseline IrO2 (and Co3O4) in pure-water MEAs despite being superior in 3-electrode alkaline liquid cells
Advancing Anion-Exchange-Membrane Water Electrolyzer Devices: Catalyst Layer Interactions, Degradation Pathways, and Operational Development · University of Oregon · PhD
Lost to a baseline
PtPdIrRhRu nanocatalyst ORR mass activity reached only 12.2% of pure platinum catalyst baseline
Multi-Principal Element Alloys Synthesis and Their Application on Electrocatalysis · Johns Hopkins · Master's
Left open by the authors
Problems the authors named and did not get to.
Left open
Elucidate the structure of residual palladium clusters and determine their catalytic mechanism for proton reduction. Blocker: Requires advanced physical characterization techniques, wet lab chemistry, and specialized spectroscopy/microscopy equipment.
Left open
Screen palladium catalysts, solvents, temperatures, and additives for the homo-coupling reaction of biferrocenyl diiodide. Blocker: Requires a wet chemistry laboratory, synthetic reagents, and analytical instruments for reaction screening
Towards the synthesis of multinuclear, branched and cyclic metallocene-containing complexes · Imperial · PhD
Left open
Resolve Pd leaching and catalyst deactivation in Pd-MIL-101-PTA during sequential tandem synthesis of caprolactam from phenol. Blocker: Requires a wet chemistry laboratory and physical catalyst synthesis and characterization apparatus.
Noble metal atoms and clusters supported on metal-organic frameworks: Structure characterization and heterogeneous catalysis · Iowa State · PhD
Left open
Develop an enantioselective decarboxylative functionalization of cyclopropenes using excited state palladium catalysis or dual photoredox/transition metal catalysis. Blocker: Requires a wet chemistry laboratory, reagents, and physical synthesis equipment.
Left open
Employ peracetic acid for the regioselective acetoxylation of triazole and oxazoline substrates using palladium catalysis. Blocker: Requires a wet chemistry laboratory and physical chemical reagents (PAA, Pd catalyst, triazole, oxazoline).
Left open
Develop enantioselective rhodium-catalyzed reductive coupling reactions using cheap, benign terminal reductants. Blocker: Requires a synthetic chemistry wet lab, reagents, catalysts, and analytical equipment
Carbon-carbon bond formation via transition metal-catalyzed transfer hydrogenative carbonyl addition · UT Austin · PhD
Left open
Expand Rh-catalyzed transfer hydrogenative coupling of alcohols to complex higher dienes beyond butadiene and isoprene. Blocker: Requires wet lab synthetic chemistry facilities, catalysts, and physical reagents
Carbon-carbon bond formation via transition metal-catalyzed transfer hydrogenative carbonyl addition · UT Austin · PhD
Left open
Extend the copper/tartramide catalyst system to cross-coupling of phenols, thiols, and alkynes in diethylene glycol. Blocker: Requires a synthetic chemistry wet laboratory, specialized reagents, and analytical equipment.
Exploring copper-catalysed Ullmann cross coupling reactions · Imperial · Doctorate
Left open
Develop atroposelective reductive biaryl cross-couplings between sterically hindered substrates using ruthenium catalysis. Blocker: Requires a synthetic chemistry wet lab, reagents, catalysts, and physical analytical equipment (e.g., HPLC, NMR).
Development of catalytic carbon-carbon bond forming reactions by leveraging the iodide effect · UT Austin · PhD
Left open
Develop catalytic perfluoroalkylation and C-C bond formation reactions using 1,3,2-diazaphospholenes while suppressing background uncatalyzed reactivity. Blocker: Requires wet lab synthetic chemistry experimentation and reagents
New Applications of 1,3,2-Diazaphospholenes in Catalysis · EPFL · PhD
Who has worked on this
Authors of the public theses cited on this page, most-cited first.
- Haosheng Feng · MIT · PhD · 2025
Chemical Sensing of N-Nitrosodimethylamine and Methane - Daniel James Lundberg · MIT · PhD · 2024
Design and Engineering of Carbon Fixing Material Systems - Michael Hurst · University of Oregon · PhD · 2022
The Oxidative Addition of Palladium(0) to Hydro- and Halo- Silanes: Mechanisms and Applications - Jingyu Feng · Imperial · PhD · 2021
Carbon electrode for the oxygen reduction reaction - Kunal Lodaya · MIT · PhD · 2026
Electrochemical Mechanisms in Thermochemical Catalysis - STEFANO SCOGNAMIGLIO · Politecnico di Torino · PhD · 2026
Development of novel catalysts for e-fuel production - Aditya Sahay · Imperial · PhD · 2025
Exploring novel strategies for C-H functionalisation of aryl boronates and asymmetric synthesis of functionalised azetidines - Carolyn E. Barnes · MIT · PhD · 2025
Synthetic Mucins for Microbial Modulation - Molly Parry · Imperial · Doctorate · 2025
Development of additives for the controlled degradation of polyethylene - Peyton David Beyer · Harvard · PhD · 2025
Addressing the Extremes of Reactivity in Small-Molecule-Catalyzed Stereoselective Glycosylation - Kaylee Lynn McCormack · MIT · PhD · 2025
Transition Metal Heterogeneous Catalysis Towards Applications in Sustainable Energy: Leveraging Rational Design Principles for Activity, Stability, and Stereoselectivity - Blake A. Johnson · MIT · PhD · 2025
Catalytic implications of confined solvent ensembles within Lewis acid zeolites
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