Impact of Surface Area in Evaluation of Catalyst Activity

Z.J. Xu is an associate professor in the School of Materials Science and Engineering, Nanyang Technological University. He is a member of the International Society of Electrochemistry (ISE) and The Electrochemistry Society (ECS), and a Fellow of the Royal Society of Chemistry (FRSC). He served as the Vice President of ECS Singapore Section. S. Sun is a postdoctoral research fellow in the School of Materials Science and Engineering, Nanyang Technological University. He received his PhD from the same institution. H. Li is a PhD student in the School of Materials Science and Engineering, Nanyang Technological University. She obtained her BS degree from the Huazhong University of Science and Technology. This article addresses the impact of surface area on the activity evaluation of an electrocatalyst. Using geometric surface area of electrodes can “boost” the catalyst activity; however, this is an artificial effect and does not reflect the intrinsic activity. This reminds us that the overpotential at 10 mA cm⁻² (by electrode surface area) should not be used as an activity evaluation standard for oxygen evolution reaction catalysts. The intrinsic activity, normalized by catalyst surface area, is recommended.