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Constructing single atom catalysts with fine-tuned coordination environments can be a promising strategy to achieve satisfactory catalytic performance. Herein, via a simple calcination temperature-control strategy, CeO₂supported Pt single atom catalysts with precisely controlled coordination environments are successfully fabricated. The joint experimental and theoretical analysis reveals that the Pt single atoms on Pt₁/CeO₂prepared at 550 °C (Pt/CeO₂-550) are mainly located at the edge sites of CeO₂with a Pt–O coordination number ofca. 5, while those prepared at 800 °C (Pt/CeO₂-800) are predominantly located at distorted Ce substitution sites on CeO₂terrace with a Pt–O coordination number ofca. 4. Pt/CeO₂-550 and Pt/CeO₂-800 with different Pt₁-CeO₂coordination environments exhibit a reversal of activity trend in CO oxidation and NH₃oxidation due to their different privileges in reactants activation and H₂O desorption, suggesting that the catalytic performance of Pt single atom catalysts in different target reactions can be maximized by optimizing their local coordination structures.

 

The pervasive use of toxic nitroaromatics in industrial processes and their prevalence in industrial effluent has motivated the development of remediation strategies, among which is their catalytic reduction to the less toxic and synthetically useful aniline derivatives. While this area of research has a rich history with innumerable examples of active catalysts, the majority of systems rely on expensive precious metals and are submicron- or even a few-nanometer-sized colloidal particles. Such systems provide invaluable academic insight but are unsuitable for practical application. Herein, we report the fabrication of catalysts based on ultralow loading of the semiprecious metal ruthenium on 2–4 mm diameter spherical alumina monoliths. Ruthenium loading is achieved by atomic layer deposition (ALD) and catalytic activity is benchmarked using the ubiquitous para-nitrophenol, NaBH4 aqueous reduction protocol. Recyclability testing points to a very robust catalyst system with intrinsic ease of handling. 

Effective control on chemoselectivity in the catalytic hydrogenation of C=O over C=C bonds is uncommon with Pd‐based catalysts because of the favored adsorption of C=C bonds on Pd surface. Here we report a unique orthorhombic PdSn intermetallic phase with unprecedented chemoselectivity toward C=O hydrogenation. We observed the formation and metastability of this PdSn phase in situ. During a natural cooling process, the PdSn nanoparticles readily revert to the favored Pd₃Sn₂phase. Instead, using a thermal quenching method, we prepared a pure‐phase PdSn nanocatalyst. PdSn shows an >96 % selectivity toward hydrogenating C=O bonds of various α,β‐unsaturated aldehydes, highest in reported Pd‐based catalysts. Further study suggests that efficient quenching prevents the reversion from PdSn‐ to Pd₃Sn₂‐structured surface, the key to the desired catalytic performance. Density functional theory calculations and analysis of reaction kinetics provide an explanation for the observed high selectivity.

 

Effective control on chemoselectivity in the catalytic hydrogenation of C=O over C=C bonds is uncommon with Pd‐based catalysts because of the favored adsorption of C=C bonds on Pd surface. Here we report a unique orthorhombic PdSn intermetallic phase with unprecedented chemoselectivity toward C=O hydrogenation. We observed the formation and metastability of this PdSn phase in situ. During a natural cooling process, the PdSn nanoparticles readily revert to the favored Pd₃Sn₂phase. Instead, using a thermal quenching method, we prepared a pure‐phase PdSn nanocatalyst. PdSn shows an >96 % selectivity toward hydrogenating C=O bonds of various α,β‐unsaturated aldehydes, highest in reported Pd‐based catalysts. Further study suggests that efficient quenching prevents the reversion from PdSn‐ to Pd₃Sn₂‐structured surface, the key to the desired catalytic performance. Density functional theory calculations and analysis of reaction kinetics provide an explanation for the observed high selectivity.