The urgent need to mitigate global climate change and transition toward sustainable energy systems has brought carbon dioxide (CO2) reduction technologies into the global spotlight. Electrochemical CO2 reduction reaction (CO2RR) stands out as a promising pathway to convert CO2, the most abundant greenhouse gas, into value-added fuels and chemicals, offering both environmental and economic benefits. At the same time, advances in material science, in-situ characterization, system-level design, and light-driven catalysis have opened new avenues for more efficient and sustainable CO2 utilization. Fundamental research on energy materials and engineering validation are also playing a crucial role in driving these technologies toward industrialization, with numerous encouraging advances being reported.
To highlight the recent progress in this critical field, Frontiers in Energy is pleased to present this special issue entitled “Electrochemical CO2 reduction for reducing CO2 emission and producing value-added products.” This thematic issue features eight invited or selected contributions, which collectively showcase recent breakthroughs in CO2RR. These work cover a broad spectrum, including catalyst material innovation, operando cell design for mechanistic insights, high-temperature solid oxide electrolysis, light-driven CO2 conversion, and bibliometric analysis of global research trends.
At the heart of progress in CO2RR lies the innovation of catalytic materials, which fundamentally determine the activity, selectivity, and stability of the reaction. This issue presents several notable advances in this domain. Zhang et al. (doi:10.1007/s11708-025-1010-8) provide a comprehensive review of high-entropy alloys (HEAs), a new class of electrocatalysts that leverage multi-element synergy and the high-entropy effect to deliver outstanding performance not only in CO2RR but also in other small molecule reduction reactions. Zhong et al. (10.1007/s11708-025-1025-1) highlights the development of a zirconium phosphate-supported palladium catalyst, in which strong metal–support interactions tune the Pd electronic structure to promote C–C coupling and achieve exceptional ethanol selectivity, with a Faradaic efficiency of 92.1%. This work exemplifies how rational support engineering can minimize noble metal use while steering the reaction pathway toward high-value C2 products over conventional C1 products.
Building on advances in materials, understanding their behavior under realistic conditions is equally essential. Wu et al. (doi: 10.1007/s11708-024-0968-y) review the recent development of electrolytic cell designs tailored for in-situ/operando synchrotron radiation characterization. These specialized cells have enabled unprecedented insights into CO2RR mechanisms at the atomic and molecular levels, providing guidance for the rational design of both catalysts and reaction environments.
Beyond low-temperature CO2RR, solid oxide electrolysis cells (SOECs) have emerged as an attractive high-temperature route for CO2 conversion, tightly integrated with renewable energy utilization. Jin et al. (doi: 10.1007/s11708-025-1012-6) provide a critical mini-review of SOECs within the power-to-X framework, highlighting their potential for large-scale carbon utilization and storage of intermittent renewable electricity in chemical form. Complementing this perspective, Li et al. (doi: 10.1007/s11708-025-1016-2) report on the integration of SOEC-based CO2 electrolysis with electrochemical oxidative coupling of methane (EOCM). By stabilizing reactive oxygen species through a composite electrode design, they demonstrate enhanced selectivity for C2 hydrocarbons, showcasing the promise of coupling CO2 utilization with methane valorization in a single system.
In parallel, light-driven CO2 reduction has attracted growing attention as an alternative and complementary approach. This issue includes two contributions focusing on photocatalytic pathways. Chen et al. (doi:10.1007/s11708-025-0996-2) review recent progress in all-inorganic and organic–inorganic hybrid metal halides, emphasizing their tunable optoelectronic properties, versatile synthesis strategies, and future potential for solar-driven CO2 conversion. Ding et al. (doi:10.1007/s11708-025-0989-1) report an innovative Z-scheme heterojunction photocatalyst, Cs3Bi2I9/WO3, which overcomes intrinsic limitations of halide perovskites through morphological and interfacial engineering, achieving nearly 99% CO selectivity and enhanced reaction rates under visible light.
Finally, to complement these mechanistic and materials-focused studies, a broader perspective on research trends is also crucial for shaping the field’s future directions. Guo et al. (doi:10.1007/s11708-025-0988-2) employ bibliometric analysis to map global research trends in catalytic CO2 reduction between 2015 and 2023. They identify key research hotspots, emerging concepts such as “selectivity” and “heterojunction,” and leading contributors and collaborations worldwide, providing a macroscopic view that can guide both funding priorities and scientific exploration.
Together, the contributions in this special issue reflect the dynamic progress in CO2 reduction research, from innovative materials and advanced characterization to system-level design, light-driven pathways, and global research trends. They also illustrate the interdisciplinary nature of the field, bridging electrochemistry, catalysis, materials science, and energy systems engineering. We hope that the insights and innovations presented here will inspire further breakthroughs toward the realization of efficient, scalable, and sustainable carbon-neutral technologies.
We would like to thank all authors for their excellent contributions and all reviewers for their constructive feedback, which have ensured the high quality of this special issue. We also extend our gratitude to the editorial office of Frontiers in Energy for their support in making this issue possible.
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