Themed collection International Year of the Periodic Table : Single Atoms as Active Catalysts

The many fundamental properties of ultrasmall noble metal nanoclusters have made it increasingly clear that they possess enormous potential for photo- and electro-catalytic applications due to their unique electronic and optical properties.

This Minireview highlights recent key developments of atomically dispersed catalytic sites for photocatalytic CO₂ reduction and elucidates the common fundamentals behind various materials systems.

SACs, DACs, and TACs, heterogeneous catalysts with the advantages of homogeneous catalysts, are ideal models for exploring catalytic mechanisms and further designing catalysts.

Introduction of recently reported single-atom catalysts and their application in the field of clean energy conversion.

Recent advances in single atom catalysts and their applications in organic chemistry are fully summarized in this review.

Pt–RuO₂ heterojunction catalysts with a unique morphology show excellent alkaline membrane fuel cell performance at an ultra-low loading Pt anode.

Presented herein is an investigation of a promising ternary metal sulfide catalyst that is capable of electrochemically converting CO₂ to liquid and gas fuels such as methanol and hydrogen.

Rhodium nanoparticles prepared by a facile laser ablation procedure show excellent activity towards the hydrogen evolution reaction.

Pre-treatment of graphitic carbon nitride (GCN) with H₂O₂ introduces active C–OH groups that can react with HAuCl₄ to immobilize single atom Au(I) in the GCN matrix through creating robust Au(I)–O coordination bonds.

Atomically dispersed Fe immobilized within N-doped carbon nanosheets was synthesized. The synergistic effect between the metal atom and its anchoring framework sites has been investigated for efficient CO₂ reduction.

Analysis and visualization of over 2121 OER catalyst compositions over pH 3–13 identifies mechanistic clusters.

Single-atomic-site Co stabilized on nitrogen and phosphorus co-doped carbon exhibits superior performance for the oxidation of substituted primary alcohols.

A three-dimensional structure consisting of atomically dispersed Fe, N-doped hollow carbon nanospheres linked by carbon nanotubes was engineered as an electrocatalyst showing a high activity for oxygen reduction reaction.

Cu-Rich PtCu octahedral alloy nanocrystals have been achieved by a composition-driven strategy and used as a robust bifunctional electrocatalyst for MOR and ORR in an acid medium.

We achieved atomic scale deposition of Pt around Au nanoparticles and enhanced Pt electrocatalysis for formic acid oxidation.

Ultralong jagged PtMo–S nanowires with rich “interfacial active sites” were fabricated by using S as the “active auxiliary” to demonstrate the enhanced catalytic HER performance triggered by the electronic and synergistic effects of PtMo/MoS_x.

Carbon fullerene fragments with low group-symmetry are highly active catalysts for the oxygen reduction reaction.

Doping of a strong-binding single-atom element into inert close-packed substrates leads to highly active and selective initial dehydrogenation at the α-C–H site of adsorbed ethanol.

Bimetallic Pd–Fe nanoalloys with tunable composition immobilized on graphitic carbon by one-pot radiolytic reduction show high electrocatalytic activity for alcohol oxidation.

TiO₂ photoanodes with {0 1 0} facets exposed show high photoelectrochemical performance and IPCE of 100% at 350 nm.

Au₂₄ without a core atom exhibits higher activity in the intramolecular hydroamination of alkynes than Au₂₅ with the core atom.

Single Mo center supported on N-doped black phosphorus is predicted to be a compelling highly efficient and durable catalyst for electrochemical N₂ fixation by density functional theory calculations.

Carbon hollow spheres (FeNPC) with single-atomic and octahedral FeN_xP_y active sites are fabricated for oxygen electrocatalysis.

A novel phenanthroline-functionalized porous organic polymer (phen-POP) has been designed, and prepared for the first time without other reactive functional groups in the polymer skeleton. Post-synthetic metalation of phen-POP with IrCl₃ afforded a single-site, highly active and selective catalyst for the hydrogenation of CO₂ to formate.

Fe₄N can play a decisive role in boosting the catalytic performance of Fe–N₄ coordination sites.

A high CO₂ to CO electroreduction rate exceeding 300 mA cm⁻² was achieved with single atom nickel and nitrogen doped three-dimensional porous carbon electrocatalysts.

The co-insertion of both cobalt and nitrogen into the carbon matrix was achieved from single precursor without any templates. The obtained Co-NSC catalyst was explored bifunctionally towards both oxygen depolarized cathode and chlorine evolution under HCl electrolysis conditions.

Developing highly efficient single-atom catalysts (SACs) containing isolated metal atom monomers dispersed on appropriate substrates has surged to the forefront of heterogeneous catalysis in recent years.

Pt single atoms, stable on alumina under O₂, form mobile clusters under H₂, due to adsorbate- and nuclearity-dependent metal-support interaction.

A heterogeneous single Cu catalyst exhibits good catalytic activity and durability at high temperature for NO reduction by CO due to the confinement effect of spinel lattice.

Atomic Fe-doped hollow carbon nanopolyhedra as efficient ORR catalysts.

By first-principles computations, nitrogen becomes activated via distal pathway on the single Ru-atom-embedded two boron monolayers, exhibiting relatively low reaction energy barriers of 0.42 and 0.44 eV, respectively.

Eight novel two-dimensional TM–TCNQ (TM = V–Zn) monolayers as highly efficient and selective electrocatalysts for CO₂ reduction have been systematically studied and the underlying detailed reaction mechanisms have been revealed.

Cobalt single atoms anchored on porphyrinic triazine frameworks exhibit high activity in ORR and HER.

Two-dimensional planar metal–organic nanosheets exhibit a superior performance to Pt-based catalysts for hydrogen evolution reaction.

Single Ag atom embedded Pt particle as novel catalyst for SO₃ decomposition. They show lower activation barrier and have potential towards better thermal resistance and better recyclability.

Single transition metal atoms supported by defective g-C₃N₄ are examined by DFT for electrochemical N₂ fixation. The single Ti atom is the most promising candidate for its high activity and stability owing to the coordination number of the active center.

Co–N₄-embedded graphene exhibits superior catalytic performance for NO electrochemical reduction with a lower onset potential than that of Pt-based catalyst.

Isolated dual transition metal atoms (Ni and Fe) were uniformly embedded into graphitic carbon nitride via a metal–N_x bond, resulting in highly efficient catalytic activity due to the electronic structure reconfiguration.

A stable single-site Rh catalyst was formed inside individual channels of three-dimensional dendritic mesoporous silica nanospheres through aminosilane binding. The catalyst demonstrated an excellent activity, stability and recyclability in the reduction of 4-nitrophenol, high regioselectivity in the hydrosilylation of terminal alkyne.

The C/N ratio of the carbon nitride lattice is tailored by doping with carbon to assess the impact on the stabilisation of palladium atoms and their catalytic efficiency in the selective hydrogenation of 2-methyl-3-butyn-2-ol.