A highly adaptable Ni catalyst for Liquid Organic Hydrogen Carriers hydrogenation

Reducing the cost of hydrogenation/dehydrogenation catalysts and improving the catalytic activity are essential steps to promote the commercial application of Liquid Organic Hydrogen Carriers (LOHCs) technology. We reported a series of highly adaptable 70 wt% Ni supported catalysts prepared by a facile co-precipitation method. The as-prepared catalysts were used in the hydrogenation of several promising LOHCs candidates, including benzene, N-propylcarbazole, N-ethylcarbazole and dibenzyltoluene. By adjusting the ratio of Al and Si, the Ni₇₀/AlSiO-1/1 catalyst with Al and Si in a molar ratio of 1:1 presents highest catalytic activity for hydrogenation of the above LOHCs, indicating the catalyst is highly adaptable for different LOHCs. The characterization results proved that the presence of SiO₂ could significantly weaken the interaction between metal and carrier and decrease the formation of NiAl₂O₄ species, which is beneficial to the reducibility of Ni. The introduced Al₂O₃ can inhibit the agglomeration of Ni and increase the dispersion of the metal. Besides, the Ni₇₀/AlSiO-1/1 catalyst was used to hydrogenate N-propylcarbazole by 5 cycles. In the fifth cycle, the hydrogen uptake reached the theoretical hydrogenation storage within 1.5 h, which suggested the excellent stability of the catalyst. Because of its low cost, high efficiency, high adaptation and highly stable, the self-made Ni catalyst has potential prospect in large-scale LOHCs application.