Hydrogenation of Nitrobenzene to Aniline With Ni/HAP Catalyst and Kinetic Studies

This study investigates the hydrogenation of nitrobenzene to aniline by using Ni/HAP catalyst under optimized conditions of 120°C, 35 bar hydrogen pressure, and 5 wt.% catalyst concentration. The process achieved 100% conversion of nitrobenzene with a 92% yield of aniline, demonstrating the high efficiency of the Ni/HAP catalytic system. A detailed kinetic study was performed to understand the reaction mechanism, with the Eley‐Rideal and Langmuir‐Hinshelwood‐Hougen‐Watson (LHHW) models evaluated for their applicability. The non‐competitive dissociative LHHW model with surface interaction between nitrobenzene and hydrogen as the rate‐limiting step was identified as the best fit, providing insights into surface adsorption and reaction dynamics. Activation energy and other kinetic parameters were calculated, confirming the catalytic efficiency and mechanistic reliability of the system. The Ni/HAP catalyst also exhibited excellent stability and reusability, making it a promising catalyst for sustainable and scalable industrial hydrogenation processes.