Regulation of Ni/Al₂O₃ catalysts by metal deposition procedures for selective hydrogenation of adiponitrile

Abstract

Understanding the essential roles in adiponitrile hydrogenation is a significant factor to design sparkling nickel catalysts. A series of Ni/Al2O3 catalysts have been synthesized by the deposition-precipitation method and used...

Selective Hydrogenation of Adiponitrile to Hexamethylenediamine by Supported Co Catalyst under Alkali-Free Conditions

“…The α peaks at lower temperatures were attributed to the chemisorption on metallic Co surface, while the β and γ peaks revealed the strong binding of adsorbed H with the Co sublayer and the spillover of hydrogen to the support, respectively. 31,32 It is worth mentioning that the H 2 desorption amount of the α peaks can be considered as an important indicator of the ability of the catalyst to activate H 2 molecules, which is exactly the temperature range for the selective hydrogenation of ADN. Combining the desorption amount of the α peak listed in Table S3, H 2 molecules could be activated at 105 °C by Co/ SiO 2 -400 and Co/AC-400 and at about 130 °C by Co/CeO 2 -400.…”

Na-Modified Al2O3-Supported Nickel-Based Catalysts for Liquid-Phase Hydrogenation of Adiponitrile: Effect of Acidity

“…The ADN hydrogenation process can be categorized into high- and low-pressure methods. The high-pressure methods employ catalysts mainly based on iron and cobalt, with stringent reaction conditions requiring higher pressures and temperatures, , whereas the low-pressure methods primarily employ catalysts Raney-type catalysts, characterized by milder reaction conditions, lower equipment requirements, and simpler processes, presenting broader commercialization prospects . However, Raney-type catalysts are prone to fragmentation and spontaneous combustion, impacting the catalyst’s lifespan and complicating the subsequent separation process. , The conventional understanding of hydrogenation processes for nitriles involves the adsorption of nitriles and hydrogen on active metal sites, followed by activation and reaction, then desorption into the solvent .…”