MXenes, a rapidly expanding family of two-dimensional (2D) materials derived from MAX phase ceramics, have emerged as transformative candidates for electrocatalysis. However, the inherent heterogeneity of surface terminations (e.g., -F, -O, -OH) inherited from synthesis often limits their potential for the hydrogen evolution reaction (HER). Herein, we report a facile surface engineering strategy to precisely modulate the surface chemistry of Ti₃C₂T_x by selectively converting detrimental -F terminations into catalytically advantageous -O groups via n-butyllithium treatment. By systematically tuning the -O/-F ratios, we demonstrate a significant enhancement in HER activity for both Pt/Ti₃C₂T_x and MoS₂/Ti₃C₂T_x heterostructures. Our findings reveal that the optimized O-rich catalysts, Pt/Ti₃C₂T_x-9 (121 mV vs. 179 mV) and MoS₂/Ti₃C₂T_x-9 (179 mV vs. 209 mV) achieve dramatically reduced overpotentials as compared to the parental F-rich analogues. Density functional theory (DFT) calculations combined with experimental characterizations unravel different enhancing mechanisms: enriched -O groups facilitate electron depletion from Pt nanoparticles to enhance H* adsorption, while conversely inducing electron accumulation on Mo sites to alleviate excessive H* binding. This work establishes a scalable methodology for tailoring the surface chemistry of MXene-based functional ceramics and provides profound insights into interfacial electronic modulation for highly efficient hydrogen production.

12CaO·7Al₂O₃ (C12A7), known as mayenite, is a major phase in calcium aluminate cement and an intermediate formed during Portland cement production. In recent years, the electride derived from C12A7 has exhibited substantial potential in catalysis and related domains. This review focuses on advances in catalysis enabled by the mayenite electride (C12A7:e⁻). We first introduce the basic concept of electrides and their historical development, and elucidate the structural features of C12A7:e⁻ alongside its distinctive position in materials science. We then systematically summarize its crystal-structural characteristics and principal synthesis strategies, analyzing how different preparation routes influence the resulting material properties. Subsequently, we highlight the performance of C12A7:e⁻ across multiple catalytic reactions, including ammonia synthesis and ammonia decomposition (cracking), and delineate its advantages in enhancing catalytic activity and selectivity. Finally, we identify key challenges for practical deployment—such as chemical stability and scalable production—and offer an outlook on expanding its applications in energy and environmental catalysis through structural tuning and process optimization.

Perovskites with a low work function find extensive applications across various fields. However, the diverse nature of perovskite compounds presents challenges for conventional trial-and-error material screening methods. In this study, we introduced an effective target-driven approach that integrates machine learning (ML) and density functional theory (DFT) calculations. Initially, we explored an exhaustive chemical space encompassing ABO₃-type single and A₂BB'O₆-type double perovskite oxides to identify stable compounds with work functions of AO-terminated (001) surfaces below 2.5 eV via a trained ML model. By employing high-precision calculations, we subsequently narrowed the selection to 27 stable perovskite oxides from the initial pool of 23,822 candidate materials. Two promising compounds, Ba₂TiWO₈ and Ba₂FeMoO₆, were then successfully synthesized and characterized experimentally. Furthermore, the first synthesized Ba₂TiWO₈ was found to exhibit catalytic activities for both NH₃ synthesis and NH₃ decomposition under mild conditions with Ru loading, suggesting its future application in catalysis. Moreover, as a Li-ion battery electrode material, Ba₂FeMoO₆ exhibited long-term cycling stability at a current density of 10 A∙g⁻¹ (10,000 cycles), revealing many possibilities for sustainable electrochemical applications of perovskites. Our work demonstrates the efficacy and efficiency of the ML-assisted method in establishing a reliable structure–property relationship for mapping work functions.

Recent studies have suggested that rare earth (RE) elements in catalysts significantly influence the performance of the ammonia synthesis. The REs appear in various forms in the ammonia synthesis catalysts including supports (oxides, hydrides, and nitrides), promotors, and intermetallic. Besides the conventional RE oxide-supporting catalysts (mainly Ru/REO), some new RE-containing catalyst systems, such as electrode and nitride systems, could drive the ammonia synthesis via a benign Mars–van Krevelen mechanism or multi-active-site mode, affording high ammonia synthesis performance under mild conditions. These works demonstrate the great potential of RE-containing catalysts for more efficient ammonia synthesis. This review summarizes the contributions of different kinds of RE-based catalysts and highlights the function mechanism of incorporated REs. Finally, an overview of this area and the challenges for further investigation are provided.

Although tin monoxide (SnO) is an interesting compound due to its p-type conductivity, a widespread application of SnO has been limited by its narrow band gap of 0.7 eV. In this work, we theoretically investigate the structural and electronic properties of several SnO phases under high pressures through employing van der Waals (vdW) functionals. Our calculations reveal that a metastable SnO (β-SnO), which possesses space group P2₁/c and a wide band gap of 1.9 eV, is more stable than α-SnO at pressures higher than 80 GPa. Moreover, a stable (space group P2/c) and a metastable (space group Pnma) phases of SnO appear at pressures higher than 120 GPa. Energy and topological analyses show that P2/c-SnO has a high possibility to directly transform to β-SnO at around 120 GPa. Our work also reveals that β-SnO is a necessary intermediate state between high-pressure phase Pnma-SnO and low-pressure phase α-SnO for the phase transition path Pnma-SnO →β-SnO → α-SnO. Two phase transition analyses indicate that there is a high possibility to synthesize β-SnO under high-pressure conditions and have it remain stable under normal pressure. Finally, our study reveals that the conductive property of β-SnO can be engineered in a low-pressure range (0–9 GPa) through a semiconductor-to-metal transition, while maintaining transparency in the visible light range.