Mechanistic Insight into the Synergetic Interaction of Ammonia Borane and Water on ZIF-67-Derived Co@Porous Carbon for Controlled Generation of Dihydrogen

Min-Hsuan Fang; Shiuan-Yau Wu; Yu-Hsiang Chang; Manmath Narwane; Bo-Hao Chen; Wei-Ling Liu; Darwin Kurniawan; Wei-Hung Chiang; Chia-Her Lin; Yu-Chun Chuang; I-Jui Hsu; Hsin-Tsung Chen; Tsai-Te Lu

doi:10.1021/acsami.1c11521

Mechanistic Insight into the Synergetic Interaction of Ammonia Borane and Water on ZIF-67-Derived Co@Porous Carbon for Controlled Generation of Dihydrogen

ACS Appl Mater Interfaces. 2021 Oct 13;13(40):47465-47477. doi: 10.1021/acsami.1c11521. Epub 2021 Oct 1.

Authors

Affiliations

¹ Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
² Department of Chemistry and R&D Center for Membrane Technology, Chung Yuan Christian University, Taoyuan 320314, Taiwan.
³ National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
⁴ Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan.
⁵ Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
⁶ Department of Molecular Science and Engineering, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan.

PMID: 34592812
DOI: 10.1021/acsami.1c11521

Abstract

Regarding dihydrogen as a clean and renewable energy source, ammonia borane (NH₃BH₃, AB) was considered as a chemical H₂-storage and H₂-delivery material due to its high storage capacity of dihydrogen (19.6 wt %) and stability at room temperature. To advance the development of efficient and recyclable catalysts for hydrolytic dehydrogenation of AB with parallel insight into the reaction mechanism, herein, ZIF-67-derived fcc-Co@porous carbon nano/microparticles (cZIF-67_nm/cZIF-67_μm) were explored to promote catalytic dehydrogenation of AB and generation of H_2(g). According to kinetic and computational studies, zero-order dependence on the concentration of AB, first-order dependence on the concentration of cZIF-67_nm (or cZIF-67_μm), and a kinetic isotope effect value of 2.45 (or 2.64) for H₂O/D₂O identify the Co-catalyzed cleavage of the H-OH bond, instead of the H-BH₂NH₃ bond, as the rate-determining step in the hydrolytic dehydrogenation of AB. Despite the absent evolution of H_2(g) in the reaction of cZIF-67 and AB in the organic solvents (i.e., THF or CH₃OH) or in the reaction of cZIF-67 and water, Co-mediated activation of AB and formation of a Co-H intermediate were evidenced by theoretical calculation, infrared spectroscopy in combination with an isotope-labeling experiment, and reactivity study toward CO₂-to-formate/H₂O-to-H₂ conversion. Moreover, the computational study discovers a synergistic interaction between AB and the water cluster (H₂O)₉ on fcc-Co, which shifts the splitting of water into an exergonic process and lowers the thermodynamic barrier for the generation and desorption of H_2(g) from the Co-H intermediates. With the kinetic and mechanistic study of ZIF-67-derived Co@porous carbon for catalytic hydrolysis of AB, the spatiotemporal control on the generation of H_2(g) for the treatment of inflammatory diseases will be further investigated in the near future.

Keywords: ammonia borane; dehydrogenation; heterogeneous catalysts; hydrogen evolution reaction; metal hydride; metal−organic framework.