A Heterodimeric Cluster‐based Pair Catalyst for Electrochemical Synthesis of Cyclohexanone Oxime

Abstract

Heterogeneous catalysts are complex chemical ecosystems, where various functional units execute their individual responsibilities to together complete a catalysis ensemble. Here we report a dinuclear catalyst originated from two molecular‐purity monomers including an atomically precise Ag4Pd2(SR)8 cluster and a polyoxotitanium Ti4O2(TBC[4])2(iPrO)4 cluster that are eventually paired off by the bridging sulfur. The heterodimeric catalyst with a unique interface consisted of the Ti‐S‐metal (metal = Pd and Ag) motifs exhibits selective recognition for nitrogen sources, thereby achieving high performances for the electrochemical synthesis of cyclohexanone oxime. The nitrate is favourably deoxygenated on the metal sites to generate nitrite, followed by the flipping of nitrite at the Ti‐S‐metal interface and the stepwise reduction of nitrite on the Ti site to produce hydroxylamine. Sequentially a spontaneous coupling from hydroxylamine and cyclohexanone proceeds to construct the C=N bond for cyclohexanone oxime. Using this combination of distinct functional modules into one catalyst, we develop a strategy for heterogeneous catalysts being designed to increase the substrate conversion while simultaneously increasing the target product selectivity.