Abstract

Significance To review the design strategies for metal particle catalysts used in the electrocatalytic CO₂ reduction reaction （eCO₂RR） in acidic media and to support further development of acidic eCO₂RR research.

Progress This review summarizes recent reports on the structural design methods of catalyst particles for acidic eCO₂RR. The current design methods for metal catalysts used in acidic eCO₂RR can be broadly categorized into organic modification， bimetallic catalysis， non-metal element doping， inorganic layer modification， and morphology control. The increased concentration of H⁺ in acidic electrolytes raises the surface-adsorbed H⁺ （*H） ratio on the electrode， enhancing hydrogen evolution reaction （HER） kinetics， which in turn leads to poor product selectivity and low activity in acidic eCO₂RR. Reducing the local H⁺ concentration on the electrode surface or increasing the adsorption selectivity of the electrode material for CO₂ and intermediates are potential methods for promoting acidic eCO₂RR.

Conclusions and Prospects In 2021， acidic eCO₂RR was first proposed. Over the past few years， some catalysts have achieved high product selectivity in acidic eCO₂RR， yet significant challenges remain：1） A method that simultaneously achieves high selectivity， high reaction rates， and high stability in acidic eCO₂RR is still lacking. Current designs for acidic catalysts often rely on alkali metal ions （e.g.， K⁺） to suppress HER and activate CO₂. However， these designs typically require the addition of high concentrations of alkali metal salts， which can lead to salt deposition， impairing gas diffusion and catalytic stability. Additionally， non-precious metal catalysts tend to dissolve in acidic media， resulting in active site loss. Encapsulating the exterior of metal particles with suitable organic or inorganic layers can improve catalytic stability to some extent but may block active sites， thereby reducing the conversion rate.2） The selectivity for single multi-electron transfer products in acidic eCO₂RR needs improvement. While some catalysts exhibit high selectivity for acidic eCO₂RR products， these products are primarily limited to CO， formic acid， and mixed C²⁺ products （e.g.， ethanol， acetic acid， ethylene， and propanol）. The selectivity for single multi-electron transfer products， such as ethylene， ethanol， or acetic acid， is much lower in acidic eCO₂RR compared to neutral or alkaline eCO₂RR. The formation mechanisms of multi-electron transfer products in acidic eCO₂RR may differ from those in neutral or alkaline eCO₂RR and require further exploration and elucidation.3） Despite numerous studies on catalyst particles with excellent eCO₂RR performance in recent years， most catalysts have the disadvantages of complex synthesis processes， limited production scalability， and inconsistent performance reproducibility. Developing efficient， easy-to-operate， and scalable synthesis methods for catalysts is a critical step toward the industrial application of eCO₂RR.4） Improvements in eCO₂RR electrolyzers are urgently needed. In addition to developing high-performance catalysts that can be produced at scale， advancements in electrolyzer design and technology are equally important for the practical application of eCO₂RR.

Keywords： electrocatalytic CO₂ reduction reaction； acidic media； surface microenvironment； electronic structure； catalyst design

Get Citation:LI Xiaopeng， HU Weibo. Review of design strategies for particle catalysts used in electrocatalytic CO2 reduction in acidic media［J］. China Powder Science and Technology，2025，31（2）：1−10.

Received:2024-09-10.Revised:2024-09-30,Online:2025-01-06.

Funding Project:国家自然科学基金项目，编号：52272289。

First Author:李小鹏（1986—），男，研究员，博士，博士生导师，上海市东方学者，研究方向为电催化。E-mail：xiaopeng. li@dhu. edu. cn。

Corresponding Author:胡维波（1987—），女，副研究员，硕士生导师，研究方向为电催化。E-mail：huwb@nbut. edu. cn。

DOI：10.13732/j.issn.1008-5548.2025.02.007

CLC No:TB4            Type Code:A

Serial No：1008-5548（2025）02-0001-10