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

Abstract

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.

Keywords:

• Ethyne semi-hydrogenation
• ethene
• bio-based support
• hemicellulosic-based gel
• Pd nanoparticle

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

This work is co-supported by the National Natural Science Foundation of China (Grant No. 21968014) and the National Key Research and Development Program of China (Grant No. 2018YFC1902105, 2018YFC1902102 and 2018YFC1902101).