Tuning proton transfer and catalytic properties in triple junction nanostructured catalyts

Nature is abundant with multi-functional and efficient catalysts such as redox enzymes which scientists wish to emulate with synthetic catalysts. One approach is to tune molecular catalysts through metal-organic ligands but there are grand challenges of molecular catalysts for real applications in energy field. Here we demonstrate a robust inorganic construct based on metal-metal oxide-carbon triple junction nanostructures (ZrO2/Pd/carbon) that mimics the functions of enzymes for highly efficient proton transport. The metal oxide tunes the local acidic environment of the metal and improves its ability for proton transport, efficient adsorption of substrate, and accelerated electron transfer. Using electrocatalytic hydrogenation (ECH) of benzaldehyde as a model reaction, we show that the intrinsic activity of the metal toward hydrogenation reaction is improved by over 200 % on the triple junction nanostructured catalysts. This study demonstrates the potential of rational design of multicomponent nanostructured catalysts to achieve enzyme like properties in synthetic catalysts.