Hydrogenolysis of Glycerol to 1,3-Propanediol: Are Spatial and Electronic Configuration of "Metal-Solid Acid" Interface Key for Active and Durable Catalysts?

Catalytic conversion of glycerol to 1,3-propanediol represents a most promising synthetic route for various specialty products in plastics, pharmaceuticals and textile industries. How to enhance chemoselectivity of 1,3-propanediol over other co-products still remains a grand challenge in this area in the past two decades. While particle size, metal-support and surface acidity have been extensively investigated for catalyst development in literature, fundamental studies on spatial and electronic configuration of "metal-solid acid" interfacial catalysts for tunable activity and selectivity are yet to be established in this field. In this context, interfacial steric hindrance and electronic transfer effect is critical for tunable activity and selectivity for metal catalysts. Therefore, in this review article, we have conducted a comprehensive and critical discussion on how steric hindrance and electronic coupling at metal-acid interfaces affect catalytic activation of internal -OH group in glycerol molecule. Selected highlights on the mechanistic investigation for ex-situ and in-situ formed Bronsted acidity over Pt-WOx and Ir-ReOx catalysts, have been discussed with experimental and computational details. The outcome of this review will provide important insights on controllable manipulation of spatial and electronic structures for selective hydrogenation reactions with broader industrial applications.