Supported Ni-Au colloid precursors for active, selective, and stable alkyne partial hydrogenation catalysts

Bimetallic NiAu catalysts have garnered broad interest for a variety of reactions including automotive emissions, selective hydrogenation, selective oxidation, hydrodechlorination, and biomass conversion. However, the bulk immiscibility of the two metals, complicating catalyst synthesis, has limited studies of this interesting bimetallic system. We report the development of a solution phase synthesis for Ni and bimetallic NiAu heterogeneous catalysts. Using oleylamine as a capping agent, an optimized synthesis for Ni catalysts led to supported particles with a narrow size distribution (4.7  0.4 nm). Gold was added to the Ni nanoparticles via galvanic displacement of Ni in organic solution, the particles were deposited onto a commercial alumina, and oleylamine capping agent removed. The catalytic activity of the bimetallic materials in 1-octyne partial hydrogenation was found to be in between the activity of monometallic Ni and Au catalysts. At high space velocity, the bimetallic catalysts largely maintai...