ABSTRACT
Liquid organic hydrogen carriers (LOHCs) are attractive platform molecules that play an important role in hydrogen energy storage and utilization. The multi-step hydrogenation of toluene (TOL) to methylcyclohexane (MCH) has been widely studied in the LOCHs systems, noble metal catalysts such as Ru has exhibited good performance in multi-step hydrogenation reactions, while the application is still hindered by their high cost and low specific activity. In this study, a series of Ru species were fabricated to investigate their structural evolution in the TOL multi-step hydrogenation reaction. The fully exposed and atomically dispersed Ru clusters, composed of an average of 3 Ru atoms, exhibit superior catalytic performance in TOL multi-step hydrogenation. Moreover, it delivers a high turnover frequency of 9850.3 h-1 under the relatively mild reaction, compared with those of single atoms and nanoparticles, and shows a notable advantage over catalysts reported in previous studies. From density functional theory calculations, the overall barrier of the TOL multi-step hydrogenation reaction over the fully exposed Ru clusters is lower than that of single atoms and nanoparticles, resulting in higher activity. This work provides an efficient strategy to regulate the reaction pathway of multi-step complicated catalytic reactions by designing fully exposed metal cluster catalysts.
ABSTRACT
A simple and efficient strategy was developed for the synthesis of Pd single-atom catalysts (PdSA/G) by nitric acid vapor-assisted redispersion. The as-prepared PdSA/G displayed robust catalytic performance in the selective hydrogenation reaction of benzaldehyde. This work paves a new way for the design of supported Pd single-atom catalysts.