As a crucial component of the carbon cycle, the reverse water-gas shift (RWGS) reaction enables the conversion of CO₂ and H₂ into CO, serving as a critical feedstock for the production of high-value-added chemicals and fuels. However, the practical application of this reaction is severely limited by three primary challenges: the poor CO₂ conversion at the relatively low and moderate temperatures, the occurrence of undesirable side reactions, such as methanation, and the high energy consumption at elevated temperatures. Consequently, the development of catalytic systems with high activity and high CO selectivity, as well as excellent structure stability, is of great importance. Platinum (Pt)-based catalysts have emerged as highly promising candidates for the RWGS reaction owing to their excellent H₂ dissociation capability, effective activation and hydrogenation capability of CO₂, and moderate adsorption strength toward reaction intermediates. In this review, recent advances in Pt-based catalysts for the RWGS reaction are systematically summarized. The innovative structural design of Pt-based catalysts is discussed in detail, followed by an in-depth analysis of the structure–performance relationship and the potential RWGS reaction mechanism via advanced characterization techniques and density functional theory (DFT) calculations. Furthermore, the remaining key scientific challenges and future development directions are highlighted, providing valuable insights for the rational design of highly efficient Pt-based catalysts for the RWGS reaction.

Bismuth (Bi)-based catalysts have been gaining recognition as the most promising catalyst materials for the electrochemical CO₂ reduction reaction (eCO₂RR) to produce formate, which provides a potential way to solve the energy crisis and the global climate crisis. However, the dynamic structural evolution of catalysts is usually observed during the operando conditions, resulting in the great difficulties for the identification of intrinsic active sites and the revelation of the structure-activity relationship at the atomic scale. This significantly hinders the development of new-type Bi-catalysts with high performance and excellent stability. This review summarizes the new findings and in-depth understanding of dynamic structural evolution for Bi-based catalysts, which are revealed by advanced in/ex situ characterization techniques. Furthermore, the dynamic structural evolution of state-of-the-art Bi-based catalysts is summarized based on the classification of derived active phase structures (e.g., metallic Bi, Bi-based alloy, and high-valence Bi sites) after reconstruction. Afterward, the surface Bi defect sites and Bi-based interface structure are strongly confirmed as the intrinsic active sites for eCO₂RR; moreover, the structure-activity relationship of Bi-based catalysts is deeply discussed based on defect engineering and interface engineering modulation. Finally, the perspectives on the future challenges and opportunities in this emerging field are presented, which facilitate to design next-gap advanced electrocatalyst with high performance for eCO₂RR.

Nickel-based layered double hydroxides (LDHs) are widely recognized as promising substitutes for noble metal catalysts in the oxygen evolution reaction (OER). However, conventional Ni²⁺ sites exhibit a high-spin configuration ( ${\text{d}}_{xz}^2{\text{d}}_{yz}^2{\text{d}}_{xy}^2{\text{d}}_{x^2-y^2}^1{\text{d}}_{z^2}^1$) with excessive frontier-orbital occupancy, resulting in weak binding strength toward oxygen intermediates, which dramatically limits their OER performance. Herein, we first report the successful construction of low-spin state Ni²⁺ ( ${\text{d}}_{xz}^2{\text{d}}_{yz}^2{\text{d}}_{xy}^2{\text{d}}_{x^2-y^2}^2{\text{d}}_{z^2}^0$) in NiCoFe-LDH (LS-NCF) through oxygen defect engineering. LS-NCF exhibits a splendid OER activity with an ultra-low overpotential of 241 mV at the current density of 1 A·cm⁻², which is 79 mV lower than that of the conventional NiCoFe-LDH with high-spin Ni²⁺ (HS-NCF), significantly outperforming previously reported transition metal-based catalysts. Comprehensive studies reveal that LS Ni²⁺ with reduced ${\text{d}}_{z^2}$ orbital occupancy effectively enhances oxygen intermediates adsorption through reinforcing the orbital hybridization between Ni 3d and O 2p. Moreover, the d-band center of LS Ni²⁺ is closer to the Fermi level compared to that of HS Ni²⁺, thus accelerating electron transfer. Consequently, the strengthened adsorption of *O intermediate and accelerated electron transfer in LS-NCF efficiently lower the reaction energy barrier of the rate-determining step (*O → *OOH), thereby greatly boosting its OER performance. This work provides valuable insights into designing high-performance Ni-based electrocatalysts via spintronic-level engineering.