No abstract

We report am ethod for the electrochemical deuteration of a,b-unsaturated carbonyl compounds under catalystand external-reductant-free conditions,w ith deuteration rates as high as 99 %a nd yields up to 91 %i n2h. The use of graphite felt for both the cathode and the anode was key to ensuring chemoselectivity and high deuterium incorporation under neutral conditions without the need for an external reductant. This method has an umber of advantages over previously reported deuteration reactions that use stoichiometric metallic reductants.M echanistic experiments showed that O 2 evolution at the anode not only eliminates the need for an external reductant but also regulates the pH of the reaction mixture,keeping it approximately neutral.

Constructing the structure and composition of active sites of catalysts to discriminate between reaction molecules remains a grand challenge in heterogeneous catalysis, as the ability to precisely control the interfacial chemistry within molecular-scale environments is largely lacking. Here, we recognize the reaction sites of thiolate-ligand protected gold nanoclusters for CO2 electroreduction (CO2RR) by cleaving the Au–S or C–S bonds selectively that can be controlled by Cd doping. Our study reveals that the C–S bond cleavage occurring on partial ligands leads to the creation of open S sites that are able to readily bind the CO2 molecule and catalyze its reduction, while the breaking of Au–S bonds creates exposed metal sites to favor H2 evolution that is considered as the main complete reaction of CO2RR. We further tailor the reactivities of these two types of reaction sites by only the ligand derivatization, which holds great promise in rational design of high-performance catalysts.