With the implementation of the carbon neutrality target all over the world, there is a growing demand for clean and sustainable energy systems. Hydrogen, as an emerging strategic secondary energy, is gathering increasing attention from academia and industry. Intensive fundamental research efforts have been devoted to accelerating the technological development of green hydrogen conversion technologies. However, the community has yet to see many successful transformations from fundamental achievements to ready technologies. The focus of this perspective is to understand the gap between scientific research and technological advancement, with an emphasis on the key materials, particularly on catalysts, which are considered the most essential core material for efficient hydrogen conversion. Based on the above discussions, prospects for the future development of the key technology for hydrogen conversion are also provided.

Enhancing the lifetime of perovskite solar cells (PSCs) is one of the essential challenges for their industrialization. Although the external encapsulation protects the perovskite device from the erosion of moisture and oxygen under various harsh conditions. However, the perovskite devices still undergo static and dynamic thermal stress during thermal and thermal cycling aging, respectively, resulting in irreversible damage to the morphology, component, and phase of stacked materials. Herein, the viscoelastic polymer polyvinyl butyral (PVB) material is designed onto the surface of perovskite films to form flexible interface encapsulation. After PVB interface encapsulation, the surface modulus of perovskite films decreases by nearly 50%, and the interface stress range under the dynamic temperature field (−40 to 85 °C) drops from −42.5 to 64.8 MPa to −14.8 to 5.0 MPa. Besides, PVB forms chemical interactions with FA⁺ cations and Pb²⁺, and the macroscopic residual stress is regulated and defects are reduced of the PVB encapsulated perovskite film. As a result, the optimized device's efficiency increases from 22.21% to 23.11%. Additionally, after 1500 h of thermal treatment (85 °C), 1000 h of damp heat test (85 °C & 85% RH), and 250 cycles of thermal cycling test (−40 to 85 °C), the devices maintain 92.6%, 85.8%, and 96.1% of their initial efficiencies, respectively.

Fe single-atom catalysts (Fe-SACs) have been extensively studied as a highly efficient electrocatalyst toward the oxygen reduction reaction (ORR). Nonetheless, they suffer from stability issue induced by dissolution of Fe metal center and the OH⁻ blocking. Herein, a surface molecular engineering strategy is developed by using β-cyclodextrins (CDs) as a localized molecular encapsulation. The CD-modified Fe-SAC (Fe-SNC-β-CD) shows obviously improved activity toward the ORR with 0.90 V, 4.10 and 4.09 mA cm⁻² for E_1/2, J₀ and J_k0.9, respectively. Meanwhile, the Fe-SNC-β-CD shows the excellent long-term stability against aggressive stress and the poisoning. It is confirmed through electrochemical investigation that modification of β-CD can, on one hand, regulate the atomic Fe coordination chemistry through the interaction between the CD and FeN_x moiety, while on the other mitigate the strong adsorption of OH⁻ and function as protective barrier against the poisoning molecules leading to enhanced ORR activity and stability for the Fe-SACs. The molecular encapsulation strategy demonstrates the uniqueness of post-pyrolysis surface molecular engineering for the design of single-atom catalyst.

As an alternative energy, hydrogen can be converted into electrical energy via direct electrochemical conversion in fuel cells. One important drawback of full cells is the sluggish oxygen reduction reaction (ORR) promoted by the high-loading of platinum-group-metal (PGM) electrocatalysts. Fe-N-C family has been received extensive attention because of its low cost, long service life and high oxygen reduction reaction activity in recent years. In order to further enhance the ORR activity, the synthesis method, morphology regulation and catalytic mechanism of the active sites in Fe-N-C catalysts are investigated. This paper reviews the research progress of Fe-N-C from nanoparticles to single atoms. The structure-activity relationship and catalytic mechanism of the catalyst are studied and discussed, which provide a guidance for rational design of the catalyst, so as to promote the more reasonable design of Fe-N-C materials.

The identification of highly active heterogeneous catalysts to replace their homogeneous counterparts remains a challenge in the case of organic catalysts, especially polymers, in highly viscous reaction systems. In this work, we designed and synthesized a novel, solid-supported, and heterogeneous pseudo-single atom Pt catalyst with high activity and recyclability. Superparamagnetic Fe₃O₄-SiO₂ core–shell nanoparticles (NPs) were used as the substrate. The functionalization of the SiO₂ shell with silane coupling agents containing vinyl groups allows stabilizing Pt on the SiO₂ surface through complexation. The as-prepared pseudo-single atom Pt displays high activity in the hydrosilylation of allyl-terminated polyether with polymethylhydrosiloxane and could be easily collected by applying a magnetic field. The Pt/vinyl/SiO₂/Fe₃O₄ catalyst can be reused for up to four reaction cycles without appreciable decrease in activity. This work demonstrates a novel strategy for the design of pseudo-single atom noble metal catalysts for processes in high-viscosity media.