부산대학교 도서관

Liquid organic hydrogen carriers have emerged as promising hydrogen storage systems, offering notable advantages over conventional storage and utilization efficiency methods. However, designing a catalyst that operates at low temperatures and remains cost-effective poses a significant challenge. We successfully synthesized Pd species (single atoms, fully exposed clusters, and nanoparticles) on a nanodiamond/graphene (ND@G) hybrid support for toluene hydrogenation. The structure of as-developed Pd catalyst was investigated by HAADF-STEM, X-ray absorption fine structure, Raman, XRD, XPS, and other characterizations. Remarkably, the Pdn/ND@G catalyst achieved a toluene conversion rate of 99.3% (100°C, 2.0 MPa H2) without loss of catalytic ability after 5 runs, which exhibited excellent catalytic performance and stable activity. Furthermore, the Pdn/ND@G catalyst exhibited an apparent activation energy as low as 62.36 ± 3.33 kJ mol-1and an initial turnover frequency of 33.1 h-1at 100°C. By adjusting the size and metal-dependent effects, we have achieved enhanced catalytic performance for toluene hydrogenation, thus paving the way for the design of efficient liquid organic hydrogen storage catalysts. Single-atom, cluster and nanoparticle Pd catalysts have been synthesized on defective nanodiamond/graphene (ND@G) by regulating the loading of metal Pd. The obtained Pd/ND@G catalysts were used for the catalytic performance of toluene hydrogenation, Pdn/ND@G catalyst with fully exposed clusters displayed better catalytic activity and higher TOF values, which compared to Pd1/ND@G and Pdp/ND@G catalysts.