Dehydrogenation of Ammonia Borane by Platinum‐Nickel Dimers: Regulation of Heteroatom Interspace Boosts Bifunctional Synergetic Catalysis

Abstract

Regulation of the atom-atom interspaces of dual-atom catalysts is essential to optimize the dual-atom synergy to achieve high activity but remains challenging. Herein, we report an effective strategy to regulate the Pt 1 -Ni 1 interspace to achieve Pt 1 Ni 1 dimers and Pt 1 + Ni 1 heteronuclear dual-single-atom catalysts (HDSACs) by tailoring steric hindrance between metal precursors during synthesis. Spectroscopic characterization reveals obvious electron transfers in Pt 1 Ni 1 oxo dimers but not in Pt 1 + Ni 1 HDSAC. In the hydrolysis of ammonia borane (AB), the H 2 formation rates show an inverse proportion to the Pt 1 -Ni 1 interspace. The rate of Pt 1 Ni 1 dimers is � 13 and 2 times higher than those of Pt 1 and Pt 1 + Ni 1 HDSAC, manifesting the interspace-dependent synergy. Theoretical calculations reveal that the bridging OH group in Pt 1 Ni 1 dimers promotes water dissociation, while Pt 1 facilitates the cleavage of BÀ H bonds in AB, which boosts a bifunctional synergy to accelerate H 2 production cooperatively.

Atom-Precise Low-Nuclearity Cluster Catalysis: Opportunities and Challenges

“…(e) Schematic diagram of the bifunctional synergy of Pt 1 Ni 1 oxo dimers. Reproduced with permission from ref , Copyright 2022 Wiley-VCH GmbH.…”

“…Recently, Pt 1 Ni 1 dimers were also synthesized on g-C 3 N 4 by combining Pt and NiO x ALD in a similar manner. 106 When the preliminary metal atoms are very dense on the carries, the deposition of additional atoms may produce direct bonding with adjacent atoms, forming ultrafine clusters. Recently, we successfully synthesized Ni 1 Cu 2 trimers on a g-C 3 N 4 support.…”

“…HAADF-STEM confirmed the dimer-like structure where the two atoms showed different contrasts (Figure e,f). Recently, Pt 1 Ni 1 dimers were also synthesized on g-C 3 N 4 by combining Pt and NiO x ALD in a similar manner …”

“…The corresponding line intensity profiles are placed at the bottom. Reproduced with permission from ref , Copyright 2022 Wiley-VCH GmbH. (e) Line intensity profile and atomic-resolution EELS elemental mapping of an individual Ni 1 Cu 2 trimer.…”

Synergistic interface between metal Cu nanoparticles and CoO for highly efficient hydrogen production from ammonia borane

“…It has been proposed in several studies that the cleavage of the O-H bond in the H 2 O molecule is the rate-determining step in the hydrolysis of NH 3 BH 3 . [43][44][45][46][47] To further elucidate this mechanism and facilitate the rational design of the catalyst, isotopic experiments on the Cu 0.5 -(CoO) 0.5 /TiO 2 catalyst were conducted using D 2 O instead of H 2 O. The kinetic isotope effect (KIE) was used reveal whether water is the rate-determining step in this reaction, with the results shown in Fig.…”