Quílez-Bermejo Javier, Strutyński Karol, Melle-Franco Manuel, Morallón Emilia, Cazorla-Amorós Diego
Departamento de Química Inorgánica and Instituto de Materiales, Universidad de Alicante, Ap. 99, Alicante 03080, Spain.
CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Aveiro 3810-193, Portugal.
ACS Appl Mater Interfaces. 2020 Dec 9;12(49):54815-54823. doi: 10.1021/acsami.0c17249. Epub 2020 Nov 25.
Metal-free carbon-based catalysts have gained much attention during the last 15 years as an alternative toward the replacement of platinum-based catalysts for the oxygen reduction reaction (ORR). However, carbon-based catalysts only show promising catalytic activity in alkaline solution. Concurrently, the most optimized polymer electrolyte membrane fuel cells use proton exchange membranes. This means that the cathode electrode is surrounded by a protonic environment in which carbon materials show poor performance, with differences above 0.5 V in for nondoped carbon materials. Therefore, the search for highly active carbon-based catalysts is only possible if we first understand the origin of the poor electrocatalytic activity of this kind of catalysts in acidic conditions. We address this matter through a combined experimental and modeling study, which yields fundamental principles on the origin of the pH effects in ORR for carbon-based materials. This is relevant for the design of pH-independent metal-free carbon-based catalysts.
在过去15年中，无金属碳基催化剂作为替代铂基催化剂用于氧还原反应（ORR）的一种选择而备受关注。然而，碳基催化剂仅在碱性溶液中表现出有前景的催化活性。同时，最优化的聚合物电解质膜燃料电池使用质子交换膜。这意味着阴极被质子环境所包围，在这种环境中碳材料表现出较差的性能，对于未掺杂的碳材料，其差值超过0.5V。因此，只有我们首先了解这类催化剂在酸性条件下电催化活性差的根源，才有可能寻找高活性的碳基催化剂。我们通过结合实验和建模研究来解决这个问题，该研究得出了关于碳基材料ORR中pH效应起源的基本原理。这对于设计与pH无关的无金属碳基催化剂具有重要意义。
