Ultrathin Metal–Organic Framework Nanosheets for Selective Photocatalytic C<sub>2</sub>H<sub>2</sub> Semihydrogenation in Aqueous Solution
Haojie Dai, Ruolan Zhang, Zhengyao Liu, Wenfeng Jiang, Yongfeng Zhou
Abstract
Abstract The selective semihydrogenation of C 2 H 2 to C 2 H 4 in crude C 2 H 4 (with ~1 vol % C 2 H 2 contamination) is a crucial process in the manufacture of polyethylene. Comparing to conventional thermalcatalytic route with Pd as catalyst under high temperature with H 2 as hydrogen source, photocatalytic C 2 H 2 reduction reaction with H 2 O as hydrogen source can achieve high selectivity under milder conditions, but has rarely been reported. Here, we present a kind of ultrathin metal–organic framework nanosheets (Cu‐Co‐MNSs) that demonstrate excellent catalytic activities in the semihydrogenation of C 2 H 2 . Employing Ru(bpy) 3 2+ as the photosensitizer, this catalyst attains a noteworthy turnover number (TON) of 2124 for C 2 H 4 , coupled with an impressive selectivity of 99.5 % after 12 h visible light irradiation. This performance is comparable to molecular catalysts and notably surpasses the efficiency of bulk metal–organic framework materials. Furthermore, Cu‐Co‐MNSs achieve a 99.95 % conversion of C 2 H 2 under industrial relevant conditions (1.10 % C 2 H 2 in C 2 H 4 ) with 90.3 % selectivity for C 2 H 4 over C 2 H 6 , demonstrating a great potential for polymer‐grade C 2 H 4 production.