Koh, Katherine Jeon, Mina Chevrier, Daniel M. Zhang, Peng Yoon, Chang Won Asefa, Tewodros 2024-01-20T02:00:32Z 2024-01-20T02:00:32Z 2021-09-01 2017-04 0926-3373 https://pubs.kist.re.kr/handle/201004/122897 The reversible reactions involving formate and bicarbonate can be used to store and release hydrogen (H-2), allowing H-2 to serve as an effective energy carrier in energy systems such as fuel cells. However, to feasibly utilize these reactions for renewable energy applications, efficient catalysts that can reversibly promote both reactions are required. Herein we report the synthesis of novel polyaniline (PANI)-derived mesoporous carbon-supported Pd nanoparticles, or materials that can efficiently catalyze these reversible reactions. The synthesis involves pyrolysis of PANI/colloidal silica composite materials at temperatures above 500 degrees C, followed by removal of the colloidal silica from the carbonized products with an alkaline solution and finally deposition of Pd nanoparticles within the mesoporous carbon products. The resulting nanomaterials efficiently catalyze the reversible reactions, i.e., the dehydrogenation of formate (HCO2- + H2O -> H-2 + HCO3-) and the hydrogenation of bicarbonate (H-2 + HCO3 -> H2O+ HCO2-). The porosity and the catalytic property of the materials can be tailored, or improved, by changing the synthetic conditions (in particular, the pyrolysis temperature and the amount of colloidal silica used for making the materials). The study further reveals that having an optimum density of N dopant species in the catalysts makes Pd to exhibit high catalytic activity toward both reactions. Among the different materials studied here, the one synthesized at 800 degrees C with relatively high amount of colloidal silica template gives the best catalytic activity, with a turnover frequency (TOF) of 2,562 h(-1) for the dehydrogenation reaction and a turnover number (TON) of 1,625 for the hydrogenation reaction. (C) 2016 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE BV OXYGEN REDUCTION REACTION FORMIC-ACID PALLADIUM ELECTROCATALYSTS SYSTEM FUTURE Novel nanoporous N-doped carbon-supported ultrasmall Pd nanoparticles: Efficient catalysts for hydrogen storage and release Article 10.1016/j.apcatb.2016.10.080 1 APPLIED CATALYSIS B-ENVIRONMENTAL, v.203, pp.820 - 828 APPLIED CATALYSIS B-ENVIRONMENTAL 203 820 828 scie scopus 000390965000081 2-s2.0-85006323990 Chemistry, Physical Engineering, Environmental Engineering, Chemical Chemistry Engineering Article ELECTROCATALYSTS SYSTEM FUTURE OXYGEN REDUCTION REACTION FORMIC-ACID PALLADIUM Hydrogen storage Hydrogen release Pd/Carbon nanomaterial Formate dehydrogenation Bicarbonate hydrogenation