Wang, X.Xu, C.Jaroniec, M.Zheng, Y.Qiao, S.-Z.2020-01-142020-01-142019Nature Communications, 2019; 10(1):4876-1-4876-82041-17232041-1723http://hdl.handle.net/2440/122674Most fundamental studies of electrocatalysis are based on the experimental and simulation results obtained for bulk model materials. Some of these mechanistic understandings are inapplicable for more active nanostructured electrocatalysts. Herein, considering the simplest and most typical electrocatalytic process, the hydrogen evolution reaction, an alternative reaction mechanism is proposed for nanomaterials based on the identification of a new intermediate, which differs from those commonly known for the bulk counterparts. In-situ Raman spectroscopy and electrochemical thermal/kinetic measurements were conducted on a series of nanomaterials under different conditions. In high-pH electrolytes with negligible hydronium (H₃O⁺) concentration in bulk phase, massive H₃O⁺ intermediates are found generating on the catalytic surface during water dissociation and hydrogen adsorption processes. These H₃O⁺ intermediates create a unique acid-like local reaction environment on nanostructured catalytic surfaces and cut the energy barrier of the overall reaction. Such phenomena on nanostructured electrocatalysts explain their widely observed anomalously high activity under high-pH conditions.en© The Author(s) 2019. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Journal article100000311310.1038/s41467-019-12773-70004928351000142-s2.0-85074166225502310Wang, X. [0000-0002-2477-8111]Xu, C. [0000-0001-9988-0447]Zheng, Y. [0000-0002-2411-8041]Qiao, S.-Z. [0000-0002-1220-1761] [0000-0002-4568-8422]