Amorphous Alloy Architectures in Pore Walls: Mesoporous Amorphous NiCoB Alloy Spheres with Controlled Compositions via a Chemical Reduction

Yunqing Kang; Bo Jiang; Juanjuan Yang; Zhe Wan; Jongbeom Na; Qian Li; Hexing Li; Joel Henzie; Yoshio Sakka; Yusuke Yamauchi; Toru Asahi

doi:10.1021/acsnano.0c07178

Amorphous Alloy Architectures in Pore Walls: Mesoporous Amorphous NiCoB Alloy Spheres with Controlled Compositions via a Chemical Reduction

ACS Nano. 2020 Dec 22;14(12):17224-17232. doi: 10.1021/acsnano.0c07178. Epub 2020 Dec 14.

Authors

Yunqing Kang^{1

2}, Bo Jiang³, Juanjuan Yang³, Zhe Wan³, Jongbeom Na⁴, Qian Li^{2

5}, Hexing Li³, Joel Henzie², Yoshio Sakka⁶, Yusuke Yamauchi^{2

4

7}, Toru Asahi^{1

7}

Affiliations

¹ Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.
² JST-ERATO Yamauchi Materials Space-Tectonics Project and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
³ The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China.
⁴ School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia.
⁵ School of Chemistry and Chemical Engineering, Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
⁶ Research Center for Functional Materials, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
⁷ JST-ERATO Yamauchi Materials Space-Tectonics Project, Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan.

PMID: 33315390
DOI: 10.1021/acsnano.0c07178

Abstract

Amorphous bimetallic borides are an emerging class of catalytic nanomaterial that has demonstrated excellent catalytic performance due to its glass-like structure, abundant unsaturated active sites, and synergistic electronic effects. However, the creation of mesoporous Earth-abundant bimetallic metal borides with tunable metal proportion remains a challenge. Herein, we develop a sophisticated and controllable dual-reducing agent strategy to synthesize the mesoporous nickel-cobalt boron (NiCoB) amorphous alloy spheres (AASs) with adjustable compositions by using a soft template-directed assembly approach. The selective use of tetrabutylphosphonium bromide (Bu₄PBr) is beneficial to generate well-defined mesopores because it both moderates the reduction rate by decreasing the reducibility of M²⁺ species and prevents the generation of soap bubbles. Our meso-Ni_10.0Co_74.5B_15.5 AASs generate the highest catalytic performance for the hydrolytic dehydrogenation of ammonia borane (AB). Its high performance is attributed to the combination of optimal synergistic effects between Ni, Co, and B as well as the high surface area and the good mass transport efficiency due to the open mesopores. This work describes a systematic approach for the design and synthesis of mesoporous bimetallic borides as efficient catalysts.

Keywords: amorphous alloys; hydrogen release; hydrolysis of ammonia borane; mesoporous materials; mesoporous metals; metal borides.