Time-resolved and theoretical analysis of Mo-carbene transformations in metathesis of ethylene with 2-butene.

Although supported Mo-containing catalysts have been extensively investigated in the metathesis of ethylene with 2-butene to propene, the mechanisms of the formation and transformation of catalytically active Mo-carbenes in the course of the reaction are still not fully understood. The difficulties arise because only a tiny fraction of MoO species can form Mo-carbenes , making the detection of the latter by spectroscopic means very unlikely. Herein, purposefully designed steady-state and transient experiments including their kinetic evaluation and density functional theory calculations enabled us to elucidate mechanistic and kinetic details of the above reaction-induced processes in the metathesis reaction over a Mo/P/SiO catalyst at 50 °C.

Mechanochemically-derived iron atoms on defective boron nitride for stable propylene production.

Single-atom catalysts (SACs), possessing a uniform metal site structure, are a promising class of materials for selective oxidations of hydrocarbons. However, their design for targeted applications requires careful choice of metal-host combinations and suitable synthetic techniques. Here, we report iron atoms stabilised on defective hexagonal boron nitride (h-BN) mechanochemical activation in a ball mill as an effective catalyst for propylene production NO-mediated oxidative propane dehydrogenation (NO-ODHP), reaching 95% selectivity at 6% propane conversion and maintaining stable performance for 40 h on stream.

CeO-Supported Single-Atom Cu Catalysts Modified with Fe for RWGS Reaction: Deciphering the Role of Fe in the Reaction Mechanism by In Situ/Operando Spectroscopic Techniques.

Reverse water-gas shift (RWGS) reaction has attracted much attention as a potential approach for CO valorization via the production of synthesis gas, especially over Fe-modified supported Cu catalysts on CeO. However, most studies have focused solely on investigating the RWGS reaction over catalysts with high Cu and Fe loadings, thus leading to an increase in the complexity of the catalytic system and, hence, preventing the gain of any reliable information about the nature of the active sites and reaction mechanism. In this work, a CeO-supported single-atom Cu catalyst modified with iron was synthesized and evaluated for the RWGS reaction.

Highly Efficient Low-loaded PdO/AlSiO Catalyst for Ethylene Dimerization.

Ethylene dimerization is an industrial process that is currently carried out using homogeneous catalysts. Here we present a highly active heterogeneous catalyst containing minute amounts of atomically dispersed Pd. It requires no co-catalyst(s) or activator(s) and significantly outperforms previously reported catalysts tested under similar reaction conditions.

Well-Defined Supported ZnO Species: Synthesis, Structure, and Catalytic Performance in Nonoxidative Dehydrogenation of C-C Alkanes.

ConspectusZinc oxide (ZnO) is a multipurpose material and finds its applications in various fields such as rubber manufacturing, medicine, food additives, electronics, etc. It has also been intensively studied in photocatalysis due to its wide band gap and environmental compatibility. Recently, heterogeneous catalysts with supported ZnO species have attracted more and more attention for the dehydrogenation of propane (PDH) and isobutane (iBDH) present in shale/natural gas.