Proton exchange membrane water electrolysis (PEMWE) is a key technology to solve the serious energy and environmental problems. However, the poor durability of electrocatalysts in acidic oxygen evolution reaction (OER) environment hinders the large-scale application of PEMWE. Herein, a robust RuMn electrochemical catalyst with a remarkable durability within 20 000 cyclic voltammetry cycles is reported. Furthermore, RuMn is stable for 720 h at 10 mA cm –2 current density in 0.5 M H 2 SO 4 solution with <100 mV overpotential increase, outperforming the most electrocatalysts reported to date, by far. An amorphous RuO x shell is detected after the OER test, indicating a surface reconstruction process on the catalyst that inhibits steady-state dissolution. Further study demonstrates that the excellent durability of RuMn realized by protective RuO x can be attributed to strong bond strength of Ru, which is supported by density functional theory calculations with high dissolution voltage. Thus, improving the bond strength of Ru extends the design strategy for the Ru-based alloy catalysts with considerable stability.
Nanoparticle incorporation is a common strategy for promoting the performance of starch-based wood adhesive as low storage stability limits the application of conventional nanocomposite adhesives. This work focuses on the performance comparison of adhesives containing different nanoparticles (nano-TiO 2 , TK (TiO 2 -KH570), TKB (TiO 2 -KH570-Butyl acrylate)) to improve both the bonding strength and storage stability. The structure and morphology of these nanoparticles are characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. The results indicate that the surface modification improves the dispersion of nano-TiO 2 . After adding in adhesive, the results of shear strength, viscosity, and rheological properties signify that the structural strength within adhesive is related to the surface hydrophobicity and the thickness of the surface hydrophobic layer of functionalized nanoparticles. TKB exhibits excellent improvement on the storage stability of adhesive due to its wide surface hydrophobic layer weakening the intermolecular interaction. TK shows limited improvement on both bonding strength and storage stability as the hanging hydrogen groups from KH570 form cross-linking structure with other components in adhesive. Therefore, selecting the appropriate functional nanoparticles is an important parameter for designing high-performance wood adhesive for the veneer industry.
Sun Baorui,Zhang Minghui,Li Junjie,Li Zhe,Wen Mingli,Liu Zhi-Quan
Ag sintering technology for die-attach application in power semiconductors has garnered significant attention in recent years due to its excellent high-temperature service reliability. In this study, a highly reliable bonding joint was achieved using a specific Ag paste, resulting in shear strength of 37.63 MPa after pressureless bonding at 250°C for 10 min. However, a significant reduction in bonding strength was observed when using another set of Ag paste with better sintering performance. To investigate this anomalous phenomenon, we have performed a series of characterizations and proposed a corresponding bonding formation mechanism. The conclusions and inferences drawn from this study offer valuable theoretical support for the further application of Ag sintering, thereby promoting the advancement of this technology. Graphical Abstract
危险品化学品经营许可证（带存储）