Jaworski, Justyn Wayne Cho, Sunghwa Kim, Yeoungyong Jung, Jong Hwa Jeon, Hyo Sang Min, Byoung Koun Kwon, Ki-Young 2024-01-20T12:34:21Z 2024-01-20T12:34:21Z 2021-09-01 2013-03-15 0021-9797 https://pubs.kist.re.kr/handle/201004/128242 The controlled generation of H-2 from storage materials by using an efficient catalytic support is a highly sought after technology; however, the majority of successes utilize expensive materials considered unfeasible. In our report on the creation of a novel, durable, and inexpensive catalytic support material for hydrogen generation, we examine a critical surface modification of hydroxyapatite (HAP) with cobalt ions to provide the necessary catalytic transition metal for the fast hydrolysis of the hydrogen storage material, sodium borohydride (NaBH4). By altering the morphology and composition of the HAP crystal supports, we revealed novel methods for enhancing the hydrogen generation rates. Particularly, lowering the Ca composition during synthesis of the HAP crystals afforded a Ca deficient HAP capable of exhibiting a higher surface coverage of cobalt, thereby eliciting faster hydrolysis reaction rates in comparison with the amorphous HAP control having the characteristic Ca content for HAP. A more significant increase in hydrogen generation was observed when using single crystal HAP in comparison with amorphous and calcium deficient HAP supports. Despite the smaller surface area of the hydrothermally prepared single crystal HAP, it provided significantly faster hydrogen generation. Each of the HAP supports exhibit repeatability with catalytic efficiency decreasing by approximately 25% over 3 weeks upon repeated daily exposure to solutions of the hydrogen storage material NaBH4. Through these experiments, we proved that altering the composition and morphology of cobalt ion exchanged HAP supports can offers a useful means for increasing the rate of controlled hydrogen generation. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved. English ACADEMIC PRESS INC ELSEVIER SCIENCE SODIUM-BOROHYDRIDE SOLUTION VISIBLE-LIGHT IRRADIATION DEFICIENT HYDROXYAPATITE HYDROLYSIS KINETICS HYDRAZINE-BORANE BORIDE CATALYSTS STORAGE MATERIAL AMMONIA-BORANE FUEL-CELL WATER Hydroxyapatite supported cobalt catalysts for hydrogen generation Article 10.1016/j.jcis.2012.11.036 1 JOURNAL OF COLLOID AND INTERFACE SCIENCE, v.394, pp.401 - 408 JOURNAL OF COLLOID AND INTERFACE SCIENCE 394 401 408 scie scopus 000315325400051 2-s2.0-84873721501 Chemistry, Physical Chemistry Article SODIUM-BOROHYDRIDE SOLUTION VISIBLE-LIGHT IRRADIATION DEFICIENT HYDROXYAPATITE HYDROLYSIS KINETICS HYDRAZINE-BORANE BORIDE CATALYSTS STORAGE MATERIAL AMMONIA-BORANE FUEL-CELL WATER Hydroxyapatite support Hydrogen generation Calcium deficient Cobalt Ion exchange