Composite strategy for enhancing dehydrogenation performance of Pd/CeO2 catalysts in dodecahydro-N-ethylcarbazole through support and active metal optimization

The N-ethylcarbazole/dodecahydro-N-ethylcarbazole system, which offers advantages such as excellent hydrogen storage capacity, good reversibility, and reliable safety, is recognized as a potential candidate for hydrogen storage. However, the inefficient dehydrogenation by existing catalysts limits the commercial application of the system. In this work, CTAB was used as the soft template to increase the specific surface area of CeO 2 supports, and further the active metals were formed upon them through various reduction methods. A series of Pd/CeO 2 catalysts were thus prepared, among which Pd/CeO 2 –C6 adopted a composite strategy of using CTAB as the template to increase the specific surface area of CeO 2 and enhancing the dispersion of Pd through ultrasound assisted reduction, showed the best catalytic dehydrogenation performance for 12H-NEC. After 7 h of reaction at 453 K, the conversion rate of 12H-NEC reached 100 % with 97.24 % of hydrogen released. Combining BET, HRTEM, XPS, CO-pulse chemisorption and other characterization analyses, it was found that the incorporation of CTAB effectively enhanced both the specific surface area and oxygen vacancy concentration of CeO 2 , while ultrasound assisted reduction enabled a small particle size and good dispersion of metal Pd on the support. The strong synergetic effects of support and active metal in Pd/CeO 2 –C6 catalyst largely accounts for its good catalytic performance. This work offers valuable insights and guidance for the development of efficient dehydrogenation catalysts for 12H-NEC.