Platinum (Pt), a precious metal extracted from minerals, plays an important role as a catalyst in energy conversion and storage devices. However, Pt is expensive and a limited resource, so it is crucial to maximize its utilization. In the electrocatalytic process, the improvement of its utilization is contingent on enhancing its mass and specific activities, a goal that can be significantly realized through the deposition of a Pt-based shell layer on a nanosubstrate material, thereby producing a core-shell structure. This review gives an important overview on the characteristics of Pt-based core-shell catalysts, the structural regulation of the core-shell, and its effects on the electrocatalytic performance. The core-shell structure can significantly increase the ratio of surface Pt atoms per unit mass of Pt particles. Moreover, the lattice mismatch between the core material and the platinum shell can generate strain, which can modulate the magnitude of the adsorption-desorption force of the platinum-based shell layer on the active intermediates, and thus contribute to the modulation of the catalytic performance. In addition to the aforementioned characteristics, the electrocatalytic performance of Pt-based core-shell catalysts is significantly influenced by the core and shell structures. The core-shell structures have unique advantages over other types of catalysts, leading to the development of advanced Pt-based catalysts.

Titanium alloys are crucial lightweight materials; however, they are susceptible to spontaneous combustion under high-temperature and high-pressure conditions, limiting their widespread use in aerospace engines. Improving the burn resistance of Ti alloys is essential for the structural safety and lightweight of aerospace equipment. Burn-resistant Ti alloys, such as Ti-V-Cr and Ti-Cu, however, face limitations such as high cost and low specific strength. Surface coatings provide a cost-effective solution while maintaining the high specific strength and good processability of the base material. Conventional surface treatments, such as laser cladding, result in defects and deformation of thin-walled parts. Cold spray technology offers a promising solution, as it uses kinetic energy to deposit coatings at low temperatures, avoiding defects and deformation. In this paper, we review the current research on burn-resistant surface technologies of Ti alloys and propose a new method of bimetallic coating by cold spraying and low-temperature heat treatment, which has the potential to solve the problem of spontaneous combustion of aerospace engine parts. The strategy presented can also guide the development of high-performance intermetallic compound-strengthened metal matrix composite coatings.

The aluminum-basalt fiber composite coating was prepared for the first time with basalt fiber as the spraying material by cold-spraying technology. Hybrid deposition behavior was studied by numerical simulation based on Fluent and ABAQUS. The microstructure of the composite coating was observed on the as-sprayed, cross-sectional, and fracture surfaces by SEM, focusing on the deposited morphology of the reinforcing phase basalt fibers in the coating, the distribution of basalt fibers, and the interaction between basalt fibers and metallic aluminum. The results show that there are four main morphologies of the basalt fiber-reinforced phase, i.e., transverse cracking, brittle fracture, deformation, and bending in the coating. At the same time, there are two modes of contact between aluminum and basalt fibers. Firstly, the thermally softened aluminum envelops the basalt fibers, forming a seamless connection. Secondly, the aluminum that has not undergone the softening effect creates a closed space, with the basalt fibers securely trapped within it. Moreover, the Rockwell hardness test and the friction-wear test were conducted on Al–basalt fiber composite coating, and the results showed that the composite coating has high wear resistance and high hardness.

As the global energy system transitions toward cleaner and low-carbon pathways, the development of efficient and durable water electrolysis technologies for hydrogen production has become increasingly crucial. The rapid expansion of renewable energy sources such as solar and wind provides abundant, clean electricity for green hydrogen production; however, their inherent intermittency and volatility often force electrolyzers to deviate from steady-state operation, resulting in efficiency losses and accelerated electrode degradation. A comprehensive understanding of degradation mechanisms under fluctuating power input is therefore essential for achieving large-scale and stable hydrogen production. This review summarizes the characteristic fluctuation patterns of renewable energy and their impacts on the operational stability of electrolytic systems. It further provides a systematic discussion of electrode degradation behaviors and dominant mechanisms under various operating conditions, including over-power, low-power, no-power, start–stop cycling, and dynamic fluctuation scenarios. Finally, key future research priorities are highlighted, emphasizing the development of multiscale degradation models, dynamic evaluation and lifetime prediction frameworks, and highly stable, adaptive electrode materials. These advances will provide critical theoretical and technological foundations for efficient, durable water electrolysis systems powered by renewable energy. Graphical Abstract