Non-noble metal-based catalysts for acetylene semihydrogenation: from thermocatalysis to sustainable catalysis

Selective semihydrogenation of acetylene in raw olefin streams to ethylene is a key industrial reaction to produce polymer-grade feeds for the manufacture of corresponding polymers. The currently used process in industry is the thermocatalytic acetylene semihydrogenation with pressurized hydrogen and Pd-based catalysts at relatively high temperatures. The high cost of Pd urgently desires the design of non-noble metal-based catalysts. However, non-noble metal-based catalysts commonly require much higher reaction temperatures than Pd-based catalysts because of their poor intrinsic activity. Therefore, aiming at increasing economic efficiency and sustainability, various strategies are explored for developing non-noble metal-based catalysts for thermocatalytic and green acetylene semihydrogenation processes. In this review, we systematically summarize the recent advances in catalytic technology from thermocatalysis to sustainable alternatives, as well as corresponding regulation strategies for designing high-performance non-noble metal-based catalysts. The crucial factors affecting catalytic performance are discussed, and the fundamental structure-performance correlation of catalysts is outlined. Meanwhile, we emphasize current challenging issues and future perspectives for acetylene semihydrogenation. This review will not only promote the rapid exploration of non-noble metal-based catalysts for acetylene semihydrogenation, but also advance the development of sustainable processes like electrocatalysis and photocatalysis.