Ru-Cluster-Modified Ni Surface Defects toward Selective Bond Breaking between C-O and C-C

For catalytic processes involving multiple reaction pathways such as the ethanol steam reforming (ESR), tailoring the active site structure of catalysts to achieve the desired catalytic selectivity is of vital importance and remains a challenge. Here, we report a heterogeneous Ru-Ni catalyst by anchoring Ru clusters onto the defect sites of Ni nanoparticles. The resulting strained Ru-Ni interface shows a high activity toward the C-C bond cleavage that is essentially required for hydrogen production via ESR. The C-O bond rupture in the side reaction (methanation) is significantly inhibited. This results in an extremely high H2 yield of 4.2 molH2/molEtOH at 350 degrees C, superior to the previously reported ESR catalysts working at medium-low temperature (300-500 degrees C). An experimental-computational combination study verifies that the conversion of Ni surface defects to the Ru-Ni interface plays a decisive role in the remarkably improved H2 yield. This work demonstrates an effective strategy to largely enhance the bond-breaking selectivity via tuning the active site structure at the catalyst surface/interface.