Catalysis Synergism by Atomically Precise Bimetallic Nanoclusters Doped with Heteroatoms

Conspectus Bimetallic catalysts hold promise in tailoringthe catalytic activityand selectivity of transition metals for important chemical processesdue to the synergistic coupling between the constituent elements thatcan connect catalytical active sites. However, it remains a challengeto construct an ideal bimetallic catalyst to study the respectiveor cooperative effects of the two transition metals within the bimetalliccatalyst on the overall catalytic performancebecause multiple factors are always convoluted, such as the size dispersityof particles, the inhomogeneous structure, and the unknown exact locationof the two metal elements in any particle. Therefore, almost all ofthe current studies give rise to the statistics of the overall catalyticperformance from all of the particles in a bimetallic catalyst orat least the observed performance reflects an ensemble average ofall metal atoms in a particle. Atomically precise metal nanoclustershave attracted catalysis scientists since their total structures (coreplus surface) were solved by single-crystal X-ray crystallography,thereby providing unparalleled opportunities to build a precise correlationof catalyst structures with catalytic properties at an atomic level.Within this field, we are interested in identifying catalyticallyactive sites and further constructing the active sites by an atom-by-atommanipulation, which are typically challenging for conventional particle-basedheterogeneous catalysts and organometallics-based complex catalysts. In this Account, we mainly focus on the extensive efforts to fundamentallyunderstand catalysis synergy in bimetallic nanocluster catalysts dopedwith heterometallic atoms. We first briefly describe the design rulesand chemical synthesis of atomically precise bimetallic nanoclustersdoped with heteroatoms including co-reduction, atom substitution,and reconstruction as typical synthesis strategies. We then put particularemphasis on the recent research toward the synergistic effects ofsurface/subsurface heteroatoms of the bimetallic nanoclusters on controllingthe catalytic pathways, in which a series of examples showed thatcatalytically active sites can be dramatically tailored by the metalheteroatoms (Ru, Cu, Ni, Cd, etc.) located on the surface or subsurfaceof gold nanoclusters. Other cases indicated that the catalytic activitycan be driven by surface heteroatom-ligand motifs of bimetallicnanoclusters. We also discuss the remote effects of nonsurface orkernel heteroatoms located in the cores of bimetallic nanoclusterson improving the catalytic reactions directly occurring on the catalystsurface. Finally, we anticipate that the advances in this researchfield would not only provide in-depth insight into the intraparticlesynergism in bimetallic catalysts for understanding and controllingtheir catalytic reactivity but also provide valuable guidelines forhigh-performance catalysts that can be applied in industry.

Automated summary

Bimetallic nanocluster catalysts show potential in tailoring catalytic activity and selectivity. Constructing ideal bimetallic catalysts is challenging due to multiple factors convoluted in the overall catalytic performance. Recent research focuses on the synergistic effects of surface/subsurface heteroatoms and core heteroatoms, providing valuable insights into intraparticle synergism and guiding the development of high-performance catalysts for industrial applications.