چكيده به لاتين
Hydrazine hydrate has been proposed as a suitable option for hydrogen storage and transportation due to its advantages such as high hydrogen content (8% wt), low cost, and stability at ambient temperature. Additionally, the ability to produce hydrogen at moderate temperatures (30-80°C) and its compatibility with the operating temperature of fuel cells, along with ease of recharging, have made hydrazine hydrate a promising source for electric fuel cell vehicles Since hydrogen can be produced from the catalytic decomposition of hydrazine, the development of active and cost-effective catalysts is desirable. In this research, nickel-based catalysts have been developed that have shown good performance and stability in the hydrazine hydrate decomposition process under mild conditions. In the initial part of this research, a La2O3 support was synthesized using a mechanochemical method, and then nickel particles were dispersed onto the surface of the support as the active component via wet impregnation. Among the synthesized catalysts, the Ni/La2O3 catalyst with 40 wt% nickel exhibited the best performance and was able to completely decompose hydrazine hydrate in the temperature range of 50-80°C, achieving 100% hydrogen selectivity. Moreover, this catalyst completed the reaction at the optimal temperature of 70°C within 15 minutes. The activation energy of this catalyst was 38 kJ/mol. This catalyst showed good stability over 10 consecutive cycles, with only a slight decrease in hydrogen selectivity after the fourth cycle. In the second part of this research, various promoters such as cobalt, copper, iron, chromium, and manganese were used to enhance the performance of the NiO(40)/La2O3 catalyst. Among the synthesized catalysts, the Ni-Co/La2O3 catalyst with 40 wt% nickel and 3 wt% cobalt exhibited the best performance. This catalyst completed the reaction within 13 minutes. The activation energy of the promoted catalyst was 28.6 kJ/mol. This sample showed good stability over 10 consecutive cycles. The synthesized samples were characterized using XRD, BET, TPR, and FESEM techniques.Decomposition of hydrazine hydrate
