The substitution of traditional fossil fuels with renewable energy sources is a crucial endeavor for achieving carbon neutrality targets. However, the intermittency of solar, wind, and other renewables poses significant challenges to the power grid. Power-to-X (P2X) technologies play an essential role in enabling the efficient consumption of renewable energy. High-temperature solid oxide electrolysis cells (SOECs) to convert CO₂ offer a promising method for CO₂ conversion, allowing renewable electricity to be stored in chemical form and facilitating the resourceful utilization of carbon resources. In this paper, the mechanism of CO₂ reduction through SOECs is reviewed, two pathways for converting CO₂ to chemicals via SOECs are summarized, and the current markets and manufacturers of SOECs are elucidated. Based on this discussion and analysis, the main challenges and development directions for the large-scale application of SOECs in CO₂ conversion are further proposed.

Carbon dioxide, as a greenhouse gas, is expected to be converted into other useful substances by the electrocatalytic CO₂ reduction reaction (CO₂RR) technology. The electrocatalytic cell, or electrochemical cell, used to provide the experimental environment for CO₂RR plays an irreplaceable role in the study of this process and determines the success or failure of the measurements. In recent years, electrolytic cells that can be applied to in-situ/operational synchrotron radiation (SR) characterization techniques have gradually gained widespread attention. However, the design and understanding of electrolyte systems that can be applied to in-situ/operational SR technologies are still not sufficiently advanced. In this paper, the electrocatalytic cells used to study the CO₂RR processes with in-situ/operando SR techniques are briefly introduced, and the types and characteristics of the electrolytic cells are analyzed. The recent advancements of in situ/operando electrolytic cells are discussed using X-ray scattering, X-ray absorption spectroscopy (XAS), light vibration spectroscopy, and X-ray combined techniques. An outlook is provided on the future prospects of this research field. This review facilitates the understanding of the reduction process and electrocatalytic mechanism of CO₂RR at the atomic and molecular scales, providing insights for the design of electrolysis cells applicable to SR technologies and accelerating the development of more efficient and sustainable carbon negative technologies.

The utilization of solar energy to address energy and environmental challenges has a seen a significant growth in recent years. Metal halides, which offer unique advantages such as tunable bandgaps, high light absorption efficiencies, favorable product release rates, and low exciton binding energies, have emerged as excellent photocatalysts for energy conversion. This paper reviews the recent advancements in both all-inorganic and organic-inorganic hybrid metal halide photocatalytic materials, including the fundamental mechanisms of photocatalytic CO₂ reduction, various synthesis strategies for metal halide photocatalysts, and their applications in the field of photocatalysis. Finally, it examines the current challenges associated with metal halide materials and explores potential solutions for metal halide materials, along with their future prospects in photocatalysis applications.

High entropy alloys (HEAs) have gained significant attention in electrocatalysis research due to their distinctive multi-element composition, intricate electronic structure, and superior properties. By harnessing multi-component synergy, precise electron regulation, and the high-entropy effect, HEA electrocatalysts exhibit remarkable catalytic activity, selectivity, and stability. These materials demonstrate outstanding catalytic performance in a variety of electrocatalytic small molecule reduction reactions, including oxygen reduction (ORR), hydrogen evolution (HER), and CO₂ reduction (CO₂RR), making them promising candidates for clean energy conversion and storage applications, including fuel cells, metal-air batteries, water electrolysis, and CO₂ conversion technologies. This review highlights recent advancements in HEA electrocatalyst research, focusing on their synthesis, characterization, and applications in electrocatalytic small molecule reduction reactions. It also explores the underlying mechanisms of the high-entropy effect, multi-component synergy, and structural design. Finally, it discusses key challenges that remain in the application of HEAs for electrocatalytic small molecule reduction and outlines potential directions for future development in this field.

The extensive utilization of fossil fuels has led to a significant increase in carbon dioxide (CO₂) emissions, contributing to global warming and environmental pollution, which pose major threats to human survival. To mitigate these effects, many researchers are actively employing state-of-the-art technologies to convert CO₂ into valuable chemicals and fuels, thereby supporting sustainable development. However, few studies have employed bibliometric methods to systematically analyze research trends in CO₂ reduction reaction (CO₂RR), resulting in limited macroscopic insights into this field. This study aims to conduct a scientometric analysis of academic literature on electrocatalytic, photocatalytic, and thermocatalytic CO₂RR from 2015 to 2023. Utilizing bibliometric analysis tools Citespace, Bibliometrix, and Vosviewer for data visualization, it establishes a knowledge framework for catalytic CO₂RR. The results show that China, the United States, and India are the top three countries with the highest number of published papers in this field, with China and the United States having the highest levels of collaboration. The journal Applied Catalysis B-Environmental published the most articles and received the highest citation count, with 3.4% of the articles in this field appearing in the journal and a total of 62526 citations. Keyword analysis revealed that terms like “CO₂RR,” “CO₂,” “conversion,” and “reduction” are the most frequently occurring, indicating key areas of focus. Additionally, “selectivity” and “heterojunction” emerged as prominent research hotspots. The discussion section highlights the current challenges in the field and proposes potential strategies to address these obstacles, providing valuable insights for research in the field of catalytic CO₂RR.

The electrochemical oxidative coupling of methane (EOCM), integrated with CO₂ electrolysis enabled by high-temperature electrolysis technology, represents a promising pathway for methane utilization and carbon neutrality. However, progress in methane activation remains hindered by low C₂ product selectivity and limited reaction activity, primarily due to the lack of efficient and stable catalysts and rational design strategies. A critical focus of current research is the development of catalysts capable of stabilizing reactive oxygen species to facilitate C–H bond activation and subsequent C–C bond formation. Herein, an easily fabricated composite electrode consisting of perovskite La_0.6Sr_0.4MnO_3–δ and Ce-Mn-W materials with (Ce_0.90Gd_0.10)O_1.95 as the support was developed, demonstrating efficient activate methane activation. Combined theoretical and experimental investigations reveal that the designed composite electrode stabilizes active oxygen species during the oxygen evolution reaction (OER) while exhibiting superior methane adsorption capability. This design, leveraging oxygen species engineering and interfacial synergy, significantly enhances electrochemical methane coupling efficiency, establishing a strategic framework for advancing high-performance catalyst development.

The photocatalytic efficiency of lead-free Bi-based halide perovskites, such as Cs₃Bi₂X₉ (X = Br, I) for CO₂ reduction is often hindered by self-aggregation and insufficient oxidation ability. In this work, a visible-light-driven (λ > 420 nm) Z-scheme heterojunction photocatalyst composed of 0D Cs₃Bi₂I₉ nanoparticles on 1D WO₃ nanorods for photocatalytic CO₂ reduction and water oxidation is synthesized using an in situ growing approach. The resulting 0D/1D Cs₃Bi₂I₉/WO₃ Z-scheme heterojunction photocatalyst exhibits a visible-light-driven photocatalytic CO₂ reduction performance for selective CO production, achieving a selectivity of 98.7% and a high rate of 16.5 μmol/(g·h), approximately three times that of pristine Cs₃Bi₂I₉. Furthermore, it demonstrates decent stability in the gas-solid photocatalytic CO₂ reduction system. The improved performance of Cs₃Bi₂I₉/WO₃ is attributed to the formation of the 0D/1D Z-scheme heterojunction, which facilitates charge transfer, reduces charge recombination, and maintains the active sites of both 0D Cs₃Bi₂I₉ for CO₂ reduction and 1D WO₃ for water oxidation. This work provides valuable insights into the potential of morphological engineering and the design of simultaneous Z-scheme heterojunction for lead-free halide perovskites.

The electrochemical CO₂ reduction reaction (CO₂RR) provides a promising approach to mitigate the global greenhouse effect by converting CO₂ into high-value chemicals or fuels. Noble metal-based nanomaterials are widely regarded as efficient catalysts for CO₂RR due to their high catalytic activity and excellent stability. However, these catalysts typically favor the formation of C1 products, which have relatively low economic value. Moreover, the high cost and limited availability of noble materials necessitate strategies to reduce their usage, often by dispersing them on suitable support materials to enhance catalytic performance. In this study, a novel metal-based support, zirconium phosphate Zr₃(PO₄)₄, was used to anchor ultrasmall palladium nanoparticles (pre-ZrP-Pd). Compared to the reversible hydrogen electrode, the pre-ZrP-Pd achieved a maximum Faradaic efficiency (FE) of 92.1% for ethanol at –0.8 V versus RHE, along with a peak ethanol current density of 0.82 mA/cm². Density functional theory (DFT) calculations revealed that the strong metal-support interactions between the ZrP support and Pd nanoparticles lead to an upward shift of the Pd d-band center, enhancing the adsorption of CO* and promoting the coupling of CO and CO to produce ethanol.