Catalytic decomposition of hydrazine nitrate is a very important research topic in the environmental protection field. Herein, we used an Ru/C catalyst for the decomposition of hydrazine nitrate in HNO₃, and the reaction kinetics and mechanism were studied in detail. The kinetics study of the decomposition of hydrazine nitrate (0.01 M) was conducted in the temperature range 313–343 K in 0.1 M HNO₃ in the presence of Ru/C. The apparent activation energy for this reaction was 46.6 kJ mol⁻¹ according to a fitting of the experimental data, while the reaction order was 1.5. It was also found that the reaction pathway of the catalytic decomposition of hydrazine nitrate on the Ru/C catalyst involved two processes: heterogeneous catalytic disproportionation of hydrazine nitrate at the catalyst surface and oxidation of hydrazine nitrate with catalytically generated HNO₂.

The 5 wt% Ru/AC catalysts were prepared using the impregnation method. The catalysts were characterized by N₂ physical adsorption, XRD, SEM, EDX, TEM and ICP-AES. The catalytic activity and stability of the catalysts in decomposing hydroxylamine nitrate (HAN) and hydrazine nitrate (HN) in nitric acid were evaluated. The results demonstrated that the Ru/AC catalyst effectively decomposed HAN and HN with complete conversion under moderate reaction conditions (60–90 °C). When used for an extended duration of 1580 hours in radioactive nitric acid waste liquid, this catalyst displayed a remarkable processing capacity of 6.32 kilograms per gram of catalyst. Due to its environmentally friendly nature resulting from harmless gas product formation along with its simple device structure design, this protocol offers practicality and economic attractiveness.

Hydroxylamine nitrate (HAN) and hydrazine nitrate (HN) are commonly found in radioactive waste solutions in nuclear fuel reprocessing, and their efficient removal is essential for waste treatment processes. In this study, six activated carbon carriers were selected to prepare Ru/AC catalysts for the simultaneous catalytic decomposition of HAN and HN, with the aim of exploring the effect of carrier properties on catalytic performance. The catalyst’s activity was evaluated in a batch reaction unit, and its structural properties were characterized using N₂ physical adsorption, XRD, SEM, and TEM techniques. The results revealed that the catalyst’s activity was primarily determined by the carrier’s particle size and specific surface area. Additionally, corrosion-induced damage to the pore structure and Ru loss were identified as the main factors responsible for catalyst deactivation. This study highlights the importance of optimizing carrier structure to enhance the activity and stability of Ru/AC catalysts.