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In this paper, the electrochemical and corrosion behavior of pure titanium (TA1) in simulated Proton Exchange Membrane Water Electrolysis (PEMWE) anodic environment was investigated. In this condition, the corrosion potential of TA1 was −689 mV, with a self-corrosion current density of 232.5 μA cm–2, and a polarization resistance of 125.9 Ω cm2. During potentiostatic polarization at 2 V, the current density was maintained at approximately 6 mA cm–2. However, the passivation process exhibited instability. Furthermore, this process has been shown to significantly facilitate the formation of surface oxides, and the passive film that formed displays the lowest bound water and OH−, and the highest content of O2–, exhibiting the highest average valence. Notably, dynamic potentials caused current transients, among which square wave potential was the most remarkable. The square wave potential shows an O2– content just below that of 2V potential polarization when fluctuating potentials are applied. The interfacial contact resistance (ICR) of 2 V potentiostatic polarization was slightly higher than that of square, sine and triangular waves. Additionally, the high temperature condition of PEMWE will aggravate the corrosion of TA1 by fluoride ions. [ABSTRACT FROM AUTHOR]

This article establishes an experimental platform for study of the thermal storage characteristics of solid thermal storage materials in low pressure environments. The experimental results show that under the influence of the thermal inertia of the heating section in low pressure environments, the thermal storage rates of thermal storage materials first increase to the peak, and then gradually decrease with the increase or decrease of the temperature of the thermal storage bricks. Air pressure has a significant impact on the heat storage rate of thermal bricks: compared to a 101kPa atmospheric pressure environment, under the same heating temperature, the heat storage time of 80kPa and 40kPa is significantly increased, and the lower the air pressure, the longer the heat storage time required.

Thermal storage ceramics using metals as phase change materials (PCMs) have both high thermal conductivity and high heat storage density. However, in the process of use is very easy to occur in the metal phase change material leakage, will seriously affect the service life of the thermal storage ceramics. In this study, ceramic composite phase change heat storage materials with Al-12Si alloy as phase change material were prepared. Firstly, Al-12Si was pretreated by sol-gel method and high temperature heat treatment to obtain the pretreated Al-12Si alloy powder with dense alumina shell layer. Afterthat, the pretreated Al-12Si alloy powder was mixed and pressed with alumina, silicon dioxide, magnesium oxide, and mullite respectively, and sintered at 1,100°C, 1,200°C, or 1,300°C. The experimental results show that the metal phase change materials and the four ceramic materials show good chemical compatibility, and pretreated Al-12Si essentially retains its initial shape and is uniformly dispersed in the heat storage material. Among all the samples, the pre-treated Al-12Si/mullite ceramic thermal storage materials with a sintering temperature of 1,200°C showed the best thermal storage performance. The thermal conductivity of the samples was up to 17.94 W/(m-K). The latent heat storage value was 139.51 J/g before thermal cycling, 138.27 J/g after 100 thermal cycling, which was only decreased by 0.89%, and there was almost no alloy leakage. This study has successfully realized that the ceramic thermal storage material possesses high thermal conductivity, high thermal storage density and excellent thermal cycling performance at the same time, and provides a new method for the production and preparation of Al-12Si/ ceramic heat storage materials, which has great potential for application in heat storage systems. [ABSTRACT FROM AUTHOR]

In this paper, a new molten salt/ceramic composite phase change thermal storage material was prepared by sol-gel method and powder compacting method. The surface of molten salt particles was encapsulated with SiO2 or TiO2 by sol-gel method, then the molten salt particles were combined with MgO to prepare composite phase change thermal storage materials. By this method, the density of the composite increased by 8.74%, the thermal conductivity increased by 16.27%, after high-temperature heat. The decline of the heat loss rate was only 2.67%. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cells have strict requirements for the CO concentration in H 2 -rich fuel gas. Here, from the perspective of industrial practicability, a highly dispersed Pt catalyst (2-4 nm) supported on activated carbon (AC), which was modified by electronic promoters (K + ) and structural promoters (isopropanol), is studied in detail. Compared with traditional metal oxide supports, the K-Pt/AC catalysts, which benefit from the tuned charge distribution, achieve a significant reduction of CO (from 1% to <0.1 ppb) under H 2 -rich conditions and show potential for used in large-scale industrial hydrogen purification. Experimental results and theoretical calculations reveal that the K atom, with its lower electronegativity, contributes to the shift of surface Pt 2+ to a lower binding energy due to the presence of oxygen species on the AC surface. This facilitates oxygen activation and accelerates desorption of the CO 2 product, thereby accelerating the reaction process and enabling the deep removal of CO in a hydrogen-rich atmosphere.