Recent progress in advanced catalysts for electrocatalytic hydrogenation of organics in aqueous conditions

Electrocatalytic hydrogenation (ECH) of organics using water as hydrogen donors has been regarded as a green organic reduction technique to replace traditional chemical reactions that use sacrificial chemicals. The development of ECH process provides potential applications in the production of value-added chemicals owing to its low energy consumption, low pollution, high safety, and superior sustainability. However, its application is limited by the low conversion rate and poor selectivity toward desired products. The efficiency of ECH can be improved by rational design of electrocatalysts. This review covers several representative electrocatalytic systems (aldehydes, ketones, phenolic organics, alkynes, and organonitrogen compounds) and summarizes different ECH mechanisms, followed by thorough discussion on the modification strategies of electrocatalysts that are currently adopted to enhance the catalytic performance. Finally, in view of the current challenges for ECH, we discuss possible future directions in the field, aiming to provide guidance to the catalyst design toward highly efficient ECH reactions over different organic feedstocks.