Coordination-driven innovations in low-energy catalytic processes: Advancing sustainability in chemical production

Metal species with different size (single atoms, nanoclusters, and nanoparticles) show different catalytic behavior for various heterogeneous catalytic reactions. It has been shown in the literature that many factors including the particle size, shape, chemical composition, metal–support interaction, and metal–reactant/solvent interaction can have significant influences on the catalytic properties of metal catalysts. The recent developments of well-controlled synthesis methodologies and advanced characterization tools allow one to correlate the relationships at the molecular level. In this Review, the electronic and geometric structures of single atoms, nanoclusters, and nanoparticles will be discussed. Furthermore, we will summarize the catalytic applications of single atoms, nanoclusters, and nanoparticles for different types of reactions, including CO oxidation, selective oxidation, selective hydrogenation, organic reactions, electrocatalytic, and photocatalytic reactions. We will compare the results obtained from different systems and try to give a picture on how different types of metal species work in different reactions and give perspectives on the future directions toward better understanding of the catalytic behavior of different metal entities (single atoms, nanoclusters, and nanoparticles) in a unifying manner.

An updated comprehensive review to help researchers understand nanozymes better and in turn to advance the field. Nanozymes are nanomaterials with enzyme-like characteristics ( Chem. Soc. Rev. , 2013, 42 , 6060–6093). They have been developed to address the limitations of natural enzymes and conventional artificial enzymes. Along with the significant advances in nanotechnology, biotechnology, catalysis science, and computational design, great progress has been achieved in the field of nanozymes since the publication of the above-mentioned comprehensive review in 2013. To highlight these achievements, this review first discusses the types of nanozymes and their representative nanomaterials, together with the corresponding catalytic mechanisms whenever available. Then, it summarizes various strategies for modulating the activity and selectivity of nanozymes. After that, the broad applications from biomedical analysis and imaging to theranostics and environmental protection are covered. Finally, the current challenges faced by nanozymes are outlined and the future directions for advancing nanozyme research are suggested. The current review can help researchers know well the current status of nanozymes and may catalyze breakthroughs in this field.

The identification of the active sites in heterogeneous catalysis requires a combination of surface sensitive methods and reactivity studies. We determined the active site for hydrogen evolution, a reaction catalyzed by precious metals, on nanoparticulate molybdenum disulfide (MoS2) by atomically resolving the surface of this catalyst before measuring electrochemical activity in solution. By preparing MoS2 nanoparticles of different sizes, we systematically varied the distribution of surface sites on MoS2 nanoparticles on Au(111), which we quantified with scanning tunneling microscopy. Electrocatalytic activity measurements for hydrogen evolution correlate linearly with the number of edge sites on the MoS2 catalyst.