Ni Single Atoms in Zeolite Beta for Selective Alkyne Hydrogenation

The removal of trace acetylene from ethylene feedstocks is essential for polyethylene production, yet current hydrogenation catalysts often suffer from over‐hydrogenation or require scarce noble metals. Here, a Pd‐free single‐atom catalyst comprising isolated Ni atoms anchored in zeolite Beta (Ni 1 /BEA) synthesized via incipient wetness impregnation on Na‐exchanged BEA zeolite is reported for selective acetylene hydrogenation. Comprehensive characterization confirmed the atomic dispersion of Ni within the BEA framework, with no evidence of Ni nanoparticle formation. Under optimized conditions (160 °C, H 2 /C 2 H 2 = 16, residence time = 0.46 s), Ni 1 /BEA achieves complete acetylene conversion with 89% ethylene selectivity, which remain stable over 24 hours with no coke formation. Ni 1 /BEA exceeds the TOF C2H2 achieved by previous zeolite‐supported single‐atom nickel catalysts by 12‐fold. Ethylene selectivity improve upon removal of Brønsted acid sites via Na + exchange, suppressing oligomerization. Ni 1 /BEA preserved the catalytic performance under industrially relevant feed containing excess ethylene, achieving 86% ethylene selectivity at full acetylene conversion. Kinetic analysis yielded consistent activation energies (≈67 kJ mol −1 ). TPD studies suggested a non‐associative hydrogenation mechanism in which H 2 activation precedes acetylene adsorption. This work demonstrates Ni 1 /BEA as a stable, cost‐effective, and Pd‐free single‐atom catalyst for acetylene removal in ethylene purification.