Hydrogen production from the catalytic dehydrogenation of dodecahydro-N-ethylcarbazole: effect of Pd precursor on the catalytic performance of Pd/C catalysts

• Published in: Environmental science and pollution research international 2021-11, Vol.28 (43), p.61623-61635
• Main Authors: Feng, Zhaolu, Chen, Xiaomin, Bai, Xuefeng
• Format: Article
• Language: English
• Subjects: Activated carbon; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Catalysts; Catalytic activity; Chemical synthesis; Dehydrogenation; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Hydrogen; Hydrogen production; N-ethylcarbazole; Nanoparticles; Palladium; Precursors; Reduction; Research Article; Ultrafines; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-15108-6

In this paper, Pd/C catalysts are synthesized via Ar glow-discharge plasma reduction using activated carbon as the support and Pd(acac) 2 , Pd(NO 3 ) 2 , K 2 PdCl 4 , and H 2 PdCl 4 as the Pd precursors, and their catalytic performances are investigated by hydrogen production from dodecahydro-N-ethylcarbazole (H12-NEC). Pd/C-A, prepared from Pd(acac) 2 , which has the smallest palladium nanoparticles (1.7 nm), the highest dispersion (34%) and no residue of inorganic ions, exhibits the best catalytic activity with a hydrogen release of 5.28 wt.%, which is 2.2 times that of Pd/C-H. The order of the apparent activation energies of the prepared Pd/C catalysts, according to the kinetics of the H12-NEC dehydrogenation reaction, is as follows: Pd/C-A ≈ Pd/C-N < Pd/C-K < Pd/C-H. When Pd(acac) 2 with a large ligand acts as a cation Pd precursor, the effect of coulombic attraction to Pd 2+ during the plasma reduction process makes it difficult for Pd nanoparticles (NPs) to migrate, which leads to the formation of ultrafine Pd NPs.