Advances in the Design of Nanostructured Catalysts for Selective Hydrogenation

Selective hydrogenations lay at the heart of many industrial processes. The archetypal catalysts for this class of reactions are generally prepared by 'metal poisoning' strategies: the active metal is protected and selectively deactivated with various compounds. This approach has been applied for decades, with limited understanding. Low product selectivity and presence of toxic elements in the catalyst pose severe constraints in the utilization of these materials in the future. Thus, to develop more sustainable catalysts, this field has recently gained momentum. This Review analyzes the concepts and frontiers that have been developed in the last decade: from nanostructuring less conventional metals in order to improve their ability to activate H2, to the use of oxides as active phases, from alloying, to the ensemble control in hybrid materials, and site isolation approaches in single-site heterogeneous catalysts. Particular attention is given to the hydrogenation of alkynes and nitroarenes, two reactions at the core of the chemical industry, importantly applied in the manufacture of polymers, pharmaceuticals, nutraceuticals, and agrochemicals. The strategies here identified can be transposed to other relevant hydrogenations and can guide in the design of more advanced materials.