Selective hydrogenation of ethyne with highly-dispersed sub-2 nm Pd nanoparticles in a hemicellulosic gel-based microreaction chamber

Ethyne is often an unwanted impurity in ethene streams used in plastics industry. Supported Pd catalysts offer high ethyne conversion, but poor ethene selectivity due to over-hydrogenation which leads to the formation of carbonaceous deposits. In this paper, acrylamide was grafted by free radical polymerization onto bagasse pith hemicellulose (to form HEMI-g-AAMs), which was then used as a porous bio-based carrier of Pd nanoparticles. The obtained Pd/HEMI-g-AAMs catalyst showed an ethyne conversion and ethene selectivity of 100% and 94.70%, respectively, at 100 °C and a space velocity of 70,000 h−1. The nitrogen-rich bio-based support regulated the physicochemical properties and catalytic activity of the supported Pd nanoparticles. Results guide the development of new and improved Pd-based catalysts for the partial catalytic hydrogenation of ethyne to ethene.