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Hydroxyapatite (HAP) supported Rh, Fe, and Rh-Fe catalysts were prepared by impregnation, and the synergy effects between the catalyst and NTP (non-thermal plasma) on N2O catalytic decomposition were also investigated. CO2-TPD results show that HAP synthesized at high pH have a greater number of surface alkaline sites and promoted the adsorption of N2O. RhFe/HAP-11 catalyst exhibited 95.9% activity for the direct catalytic decomposition of N2O at 350 °C. Combining NTP with the RhFe/HAP-11 catalyst can significantly enhance the catalytic decomposition of N2O and greatly reduce the reaction temperature. The one-stage combination method enables the radicals generated by the plasma to participate in the reaction immediately on the catalyst surface, so it is more conducive to the N2O catalytic decomposition in the range of 150–200 °C. When NTP is applied, N2O conversion on RhFe/HAP-11 at 200 °C increases a lot from 7.1 to 90.0%. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA) is a promising membrane material for pervaporation (PV) desalination. However, the adjustment and control of the cross‐linking structure is still a challenge for PVA membrane. In this study, a novel pH‐resistant PVA‐based composite membrane for efficient pervaporation desalination was developed by precisely adjusting the cross‐linking behavior. Vinyl alcohol‐vinylamine copolymer (VA‐co‐VAm) containing both hydroxyl and amino groups was synthesized. Cross‐linking reaction was carried out based on the Schiff base reaction between amino groups (in VAm moiety) and glutaraldehyde (GA) under alkaline conditions. Cross‐linking degree of PVA selective layer was carefully controlled by adjusting the amino group content in copolymer. Results showed that membrane prepared with VA‐co‐VAm that containing 5 wt% N‐vinylformamide (NVF) displayed superior hydrophilicity and the largest free volume fraction. Pervaporation test indicated that the modified cross‐linking membrane showed good stability under extreme pH conditions. Specifically, under strong acid conditions (pH ~ 1) and alkaline conditions (pH ~ 14), the membrane showed excellent desalination performance with water flux over 12 kg/(m2 h), and the salt rejection higher than 99.95%. Based on the above results, the prepared membrane offers a promising platform for desalination under extreme pH conditions, which shows great potential in industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is a common greenhouse gas and urgent need to be contained. Direct catalytic decomposition of N2O by high activity catalyst into N2 and O2 is a low-cost and harmless method. Bimetallic catalysts show good catalytic activity in many classes of reactions, and plasma technologies, applied to prepare of catalyst, are considered to be a promising method. In our contribution, DBD cold plasma is applied to synthesize Rhodium and Cobalt bimetallic catalysts for catalytic N2O decomposition. The influence of cobalt and rhodium content on N2O decomposition activity shows that the optimal amount of metal is determined as 5wt. % cobalt and 0.5wt. % rhodium loaded on Al2O3. The best working voltage is determined as 18kV. The results indicated that the Rh/Al2O3 catalysts prepared by atmospheric-pressure DBD cold plasma showed smaller size and high dispersion of Rh particles, so that the metal-support interaction and the catalytic activity are enhanced. Atmospheric-pressure DBD cold plasma is proved to be an environmentally friendly and efficient method for preparing high performance Rhodium and Cobalt bimetallic catalysts for catalytic N2O decomposition.