Hydroformylation of Olefins by a Rhodium Single‐Atom Catalyst with Activity Comparable to RhCl(PPh₃)₃

Abstract

Homogeneous catalysts generally possess superior catalytic performance compared to heterogeneous catalysts. However, the issue of catalyst separation and recycling severely limits their use in practical applications. Single-atom catalysts have the advantages of both homogeneous catalysts, such as "isolated sites", and heterogeneous catalysts, such as stability and reusability, and thus would be a promising alternative to traditional homogeneous catalysts. In the hydroformylation of olefins, single-atom Rh catalysts supported on ZnO nanowires demonstrate similar efficiency (TON≈40000) compared to that of homogeneous Wilkinson's catalyst (TON≈19000). HAADF-STEM and infrared CO chemisorption experiments identified isolated Rh atoms on the support. XPS and XANES spectra indicate that the electronic state of Rh is almost metallic. The catalysts are about one or two orders of magnitude more active than most reported heterogeneous catalysts and can be reused four times without an obvious decline in activity.

One‐Pot Cooperation of Single‐Atom Rh and Ru Solid Catalysts for a Selective Tandem Olefin Isomerization‐Hydrosilylation Process

“…[2] Their cationic nature,m onoatomicity and defined coordination environment make oxide-supported SACs excellent candidates to bridge the gap between the disciplines of heterogeneous and homogeneous catalysis, [3] particularly in an umber of areas which have been traditionally dominated by molecular complex catalysts applied in solution. Hence, SACs have been recently explored for reactions classically catalyzed by cationic metal salts or complexes,i ncluding olefin hydroformylation, [5] olefin hydrosilylation, [6] alkyne hydrochlorination, [7] or C À Ccoupling. [8] Arelevant area where SACs can have aprofound impact is tandem catalysis,that is,the integration of two catalysts in as ingle pot to achieve sequential transformations in adirect manner.…”

Single-Atom Catalysis: How Structure Influences Catalytic Performance

“…The idea is then to target reactions typically performed by organometallic compounds in solution, and try to “heterogenize” the reaction using the same metal. Both Lang et al [66] and Wang et al [67] have demonstrated oxide supported Rh-SACs can catalyse hydroformylation of olefins as well as Rh-based homogeneous catalysts. In the latter case, the authors proposed an intriguing reaction pathway in which H 2 dissociation occurs at Rh adatoms leading to surface OH groups, which take part in the reaction with CO and propene coadsorbed at Rh 1 .…”

Fabrication of Superior Single‐Atom Catalysts toward Diverse Electrochemical Reactions

“…It is thus demonstrated that this method could be employed to synthesize single atoms. Subsequently, they also proved that this method could be applied to prepare other metal atoms, such as single Ir atoms on FeO x and single Rh atoms on ZnO …”