The Catalytic Consequence of Isolated Ni Single-Atoms in BEA Zeolite for Hydrogen Production and Olefin Conversion

In our previous work, we fabricated Ni single-atoms within Beta zeolite (Ni1@Beta-NO3−) using NiNO3·6H2O as a metal precursor without any chelating agents, which exhibited exceptional performance in the selective hydrogenation of furfural. Owing to the confinement effect, the as-encapsulated nickel species appears in the form of Ni0 and Niδ+, which implies its feasibility in metal catalysis and coordination catalysis. In the study reported herein, we further explored the hydrogen production and olefin oligomerization performance of Ni1@Beta-NO3−. It was found that Ni1@Beta-NO3− demonstrated a high H2 generation turnover frequency (TOF) and low activation energy (Ea) in a sodium borohydride (NaBH4) hydrolysis reaction, with values of 331 min−1 and 30.1 kJ/mol, respectively. In ethylene dimerization, it exhibited a high butylene selectivity of 99.4% and a TOF as high as 5804 h−1. In propylene oligomerization, Ni1@Beta-NO3− demonstrated high selectivity (75.21%) of long-chain olefins (≥C6+), overcoming the problem of cracking reactions that occur during oligomerization using H-Beta. Additionally, as a comparison, the influence of the metal precursor (NiCl2) on the performance of the encapsulated Ni catalyst was also examined. This research expands the application scenarios of non-noble metal single-atom catalysts and provides significant assistance and potential for the production of H2 from hydrogen storage materials and the production of valuable chemicals.