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oai:riuma.uma.es:10630/399892026-02-03T12:24:32Zcom_10630_2254col_10630_37959

Preparation and Properties of Proton Conductors and HER Electrocatalysts Based on Multifunctional Transition Metal Sulfophosphonates. Vílchez-Cózar, Álvaro Salcedo, Inés R. Xanthopoulos, Konstantinos Pérez-Colodrero, Rosario Mercedes Bazaga-García, Montse Demadis, Konstantinos D. Olivera-Pastor, Pascual Cabeza-Díaz, Aurelio Rayos X - Difracción Estructura cristalina (Sólidos) Sincrotrones Catalizadores de metales de transición Preparation and Properties of Proton Conductors and HER Electrocatalysts Based on Multifunctional Transition Metal Sulfophosphonates Transition metal phosphonates are multifunctional materials with potential applications in energy storage and conversion technologies [1]. These materials exhibit proton-conducting properties and are attractive precursors for the preparation of electrocatalysts [2,3]. Thus, their structurally tunable properties facilitate, on one hand, the formation of efficient proton transport pathways, and on the other, their pyrolytic conversion into electrocatalytically active transition metal phosphides or polyphosphates [4]. Herein, we report the synthesis, structural diversity, and electrochemical characterization of a series of transition metal sulfophosphonates (M = Mn2+, Fe2+, Co2+, Zn2+) derived from 2-[bis(phosphonomethyl)amino]ethanesulfonic acid (SPA). Their crystal structures were determined using synchrotron and laboratory X-ray powder diffraction, allowing structure–property correlations to be established. Depending on the material composition, the proton conductivity values ranged from 10-4 S·cm-1 (Mn2+, Fe2+, and Co2+ derivatives) to 10-2 S·cm-1 (mixed NH4+/Zn2+ derivative) at 80°C and 95% relative humidity, with all compounds exhibiting a water-mediated proton transfer mechanism. In addition, among the transition metal materials pyrolyzed under (5%)H2–Ar atmosphere, the Co-based derivative treated at 700°C, consisting of mixed o-CoP and o-Co2P phases, exhibited the best performance in the hydrogen evolution reaction (HER), achieving overpotentials of only 91 and 95 mV at 10 mA·cm-2 under acidic and alkaline conditions, respectively, when supported on a CFP substrate. References [1] P. Bhanja, J. Na, T. Jing, J. Lin, T. Wakihara, A. Bhaumik, Y. Yamauchi. Chem. Mater. 31 (2019), 5343–5362. [2] S.-S. Bao, G.K.H. Shimizu, L.-M. Zheng. Coord. Chem. Rev. 378 (2019), 577–594. [3] R. Zhang, S.M. El-Refaei, P.A. Russo, N. Pinna. J. Nanopart. Res. 20 (2018), 146. [4] Á. Vílchez-Cózar, R. M. P. Colodrero, M. Bazaga-García, D. Marrero-López, S. M. El-Refaei, P. A. Russo, N. Pinna, P. Olivera-Pastor, A. Cabeza. Appl. Catal. B 337 (2023), 122963. 2025-09-22T11:18:00Z 2025-09-22T11:18:00Z 2025 conference output https://hdl.handle.net/10630/39989 eng 5th International Conference on Phosphonate Chemistry, Science, and Technology (ICOPHOS-5) Perugia (Italia) 17 al 19 de Septiembre de 2025 PID2019-110249RB-I00 TED2021-129836B-I00 PID2023-148883OB-I00 B1-2023_006 (UMA) PRE2020-094459 open access