Advanced heterolytic H2 adsorption of K-added Ru/MgO catalysts for accelerating hydrogen storage into aromatic benzyltoluenes

Herein, we report a highly active K-added Ru/MgO catalyst for hydrogen storage into aromatic benzyltoluenes at low temperatures to advance liquid organic hydrogen carrier technology. The hydrogenation activity of Ru/K/MgO catalysts exhibits a volcano-shaped dependence on the K content at the maximum with 0.02 wt%. This is in good agreement with the strength and capacity of H2 adsorption derived from basicity, despite a gradual decrease in the textural property and the corresponding increase in the Ru particle size with increasing the K content. Density functional theory calculations show that heterolytic hydrogen adsorption properties (strength and polarization) are facilitated up to a specific density of K on the Ru-MgO interface and excessive K suppresses heterolytic H2 adsorption by direct interaction between K and hydrogen, assuring the hydrogenation activity and H2 adsorption capability of Ru/K/ MgO catalysts. Hence, the Ru/K/MgO catalyst, when K is added in an optimal amount, is highly effective to accelerate hydrogen storage kinetics at low temperatures owing to the enhanced heterolytic H2 adsorption. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

A highly active K-added Ru/MgO catalyst was reported for hydrogen storage into aromatic benzyltoluenes at low temperatures to advance liquid organic hydrogen carrier technology.