摘要
Spectroscopic study of water splitting by neutral metal clusters is crucial to understanding the microscopic mechanism of catalytic processes but has been proven to be a challenging experimental target due to the difficulty in size selection.Here,we report a size-specific infrared spectroscopic study of the reactions between neutral group 3 metals and water molecules based on threshold photoionization using a vacuum ultraviolet laser.Quantum chemical calculations were carried out to identify the structures and to assign the experimental spectra.All the M_(2)O_(4)H_(4)(M=Sc,Y,La)products are found to have the intriguing M_(2)(μ_(2)-O)(μ_(2)-H)(μ_(2)-OH)(η^(1)-OH)_(2) structures,indicating that the H-OH bond breaking,the M-O/M-H/M-OH bond formation,and hydrogen production proceed efficiently in the reactions between laser-vaporized metals and water molecules.The joint experimental and theoretical results on the atomic scale demonstrate that the water splitting by neutral group 3 metals is both thermodynamically exothermic and kinetically facile in the gas phase.These findings have important implications for unravelling the structure-reactivity relationship of catalysts with isolated metal atoms/clusters dispersed on supports.
基金
the Dalian Coherent Light Source (DCLS) for support and assistance
supported by the National Key Research and Development Program of China (No.2021YFA1400501)
the National Natural Science Foundation of China (Nos.22125303,92061203,92061114,21976049,22103082,22273101 and 22288201)
the Youth Innovation Promotion Association of the Chinese Academy of Sciences (CAS)(No.2020187)
Innovation Program for Quantum Science and Technology (No.2021ZD0303304)
CAS (No.GJJSTD20220001)
Dalian Institute of Chemical Physics (No.DICP DCLS201702)
International Partnership Program of CAS (No.121421KYSB20170012)
K.C.Wong Education Foundation (No.GJTD-2018-06).