Preparation of MCM-41 supported Ni@Pd core-shell nanocatalysts by ultrasound-assisted galvanic replacement and their efficient catalytic dehydrogenation of dodecahydro-N-ethylcarbazole

Abstract

N-ethylcarbazole (NEC) is one of the most promising liquid organic hydrogen carriers (LOHCs) due to its low dehydrogenation enthalpy. The development of an efficient catalyst for the dehydrogenation of dodecahydro-N-ethylcarbazole (H12-NEC) is the key to the large-scale application of LOHCs. In this paper, Ni/MCM-41 was prepared by chemical reduction method using MCM-41 as the carrier, and then MCM-41 loaded Nin@Pd1 core-shell nanocatalysts (Nin@Pd1/M41) were prepared by ultrasound-assisted galvanic replacement method using Ni as the templating agent and reducing agent. It was shown that there was electron transfer between Ni and Pd, and SMSI effect of Nin@Pd1 with MCM-41 by the characterization results of Nin@Pd1/M41, which promoted the catalytic performance. H12-NEC dehydrogenation efficiency over Ni6@Pd1/M41 reached 100% at 180 °C for 4 h and at 170 °C for 6 h, and 97.58% for 6 h at 160 ℃, and TOF was 5080.6 h−1, which was better than that reported in the literature. The excellent catalytic dehydrogenation performance of Ni6@Pd1/M41 can mainly be attributed to the synergistic effect of coordination and strain effects between the bimetals.