Cobaloxime-based homogeneous and metal-organic framework photocatalytic systems for selective reduction of acetylene to ethylene

03 June 2024, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The semi-hydrogenation of acetylene to ethylene in ethylene-rich gas streams is an industrially important chemical reaction for producing polymer-grade ethylene. Traditional thermocatalytic routes for acetylene reduction to ethylene, despite progress, still require high temperatures and high H2 consumption, possess low selectivity, and use a noble metal catalyst. Light-powered strategies are starting to emerge, given that they have the potential to use directly the abundant and sustainable solar irradiation. Here we report >99.9% selective, visible-light powered, catalytic conversion of acetylene to ethylene. Our catalyst is a homogeneous molecular cobaloxime that operates in tandem with a photosensitizer at room temperature and bypasses the use of non-environmentally friendly and flammable H2 gas feed. The reaction proceeds through a cobalt-hydride intermediate with nearly 100% conversion of acetylene under competitive (ethylene co-feed) conditions after only 50 minutes, and with no evolution of H2 or overhydrogenation to ethane. We further incorporate the cobaloxime as linker in a metal-organic framework; the result is a heterogeneous catalyst for the conversion of acetylene under competitive (ethylene co-feed) conditions that can be recycled up to six times and remains catalytically active for 48 hours, before significant loss of performance is observed.


Acetylene reduction

Supplementary materials

Supplementary Information
Contains detailed Materials and Methods, as well as Supplementary Figures for the main text.


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