Acid-treated bentonite-supported Ni catalysts via rapid microwave-assisted drying for nitrobenzene hydrogenation

ABSTRACT

Acid-treated bentonite-supported Ni catalysts were prepared using a microwave-assisted drying process, characterized and used for the hydrogenation of nitrobenzene to aniline. Microwave-assisted drying of the catalyst reduced the drying time from 3 h with a traditional heating method to 10 min; after drying by microwave irradiation, the acid-treated bentonite-supported Ni catalysts were more stable due to a smaller crystallite size, a higher dispersion of metallic Ni and stronger interactions between Ni and the acid-treated bentonite support than the traditional drying method. Catalytic studies conducted at 300°C with a nitrobenzene liquid hourly space velocity of 3.6 mL g⁻¹ h⁻¹ and a H₂ gas hourly space velocity of 4,800 mL g⁻¹ h⁻¹ indicated that the catalyst prepared using the microwave heating method maintained a nitrobenzene conversion of >99.9% with an aniline selectivity >93% during a 60-h reaction. In addition, the catalyst dried using a traditional method only functioned for 16 h.

KEYWORDS:

• Aniline
• chemisorption
• hydrogenation
• microwave-assisted drying
• Ni/acid-treated bentonite
• nitrobenzene

Additional information

Funding

This work supported by the National Natural Science Foundation of China (21566005, 21425627), Guangxi Natural Science Foundation (2014GXNSFAA118049), the Open Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology (2013K011), and Patent project of colleges and universities of Guangxi Zhuang Autonomous Region (KY2015ZL001).