Preparation And Catalytic Properties Of Polymer/Raney Catalyst Composites

A new type of sesame-ball-like plastic/Raney catalyst composites and the corresponding preparation procedures were originated. These sesame-ball-like polymer/Raney catalyst composites, suitable for low-temperature reactions, possessed both the high catalytic activity of Raney catalysts and the excellent processibility and recyclability of plastics. The alkalescent polyamide6(PA6) matrix was composed with Raney Ni catalyst to enhance the selectivity and to reduce or even eliminate side reactions caused by the acidity of traditional catalyst supports. And this new type of PA6/Raney Ni composites achieved clean preparation of n-butanol. Meanwhile, PA6adsorption mechanism, explaining for n-butanol clean preparation, was presented. Besides,100kg of PA6/Raney Ni composites for commercial plant assessment were produced successfully with the help of vacuum suction applied to accelerate the preparation of PA6/Ni-Al alloy composite granules, the precursor of PA6/Raney Ni composites.The polymer matrix can provide more eco-friendly catalyst preparation and recycling processes than those of traditional Al2O3and SiO2supports. Polymer composed catalysts do not need calcinations at high temperatures and hydrogen reduction as traditional Al2O3-supported catalysts need; therefore, energy and hydrogen consumption can also be reduced. Furthermore, the recycling of polymer composed catalysts need only calcining in air to get rid of polymer and the remaining metal alloys could be reused directly. In contrast, the recycling of the traditional supported catalysts needs to use nitro-hydrochloric acid, which produces a lot of NOx and the acid-solublized metals are difficult to be separated. As a series of important Raney metal catalysts, including but not limited to Raney nickel, Raney cobalt, and Raney copper, are routinely used in our chemical industry, we believe that the use of polymers as catalyst matrix can be leveraged to the whole catalyst family to achieve green chemistry by eliminating side reactions and cutting down resources and energy consumption caused by the side reaction in chemical industries.Furthermore, PA6/Raney Ni composites were also applied in hydrogenation reaction of acetone, hydroamination reaction of acetone, refining reaction of ethylene glycol, and methanation reaction of carbon monoxide. PA6/Raney Ni composites achieved clean preparation of isopropanol, but had terrible catalytic selectivity to isopropylamine. The results of these two reactions verified PA6adsorption mechanism from different aspects. Meanwhile, PA6/Raney Ni composites showed great catalytic properties in refining reaction of ethylene glycol, indicating PA6/Raney Ni composites’ applicability in industrial decontamination of trace aldehydes, ketones, and carboxylic acids, and in refining of commercial products. Also, PA6/Raney Ni composites showed superior applicability in methanation reaction of carbon monoxide, one of no-selectivity-issue reactions.Finally, derived from the practicability of certain plastics’ carbonization in high-temperature and oxygen-insulated condition, C/Raney catalyst composites were prepared, which completely solved the heat resistant problem of plastic/Raney catalyst composites and significantly widened the application range of this type of composed catalysts. C/Raney catalyst composites were preliminarily considered suitable for500℃-below oxidative reactions and high-temperature non-oxidative reactions. Moreover, C/Raney Ni composites were also applied in hydrogenation reaction of n-butyraldehyde, refining reaction of ethylene glycol, and methanation reaction of carbon monoxide. Owing to the cage-like structure and restrained activity decrease by H2reserved in in-situ CNTs, C/Raney Ni composites showed extremely high catalytic activity in these three reactions. More importantly, based on adsorption mechanism presented in this study, it was believed, the catalytic selectivity of C/Raney Ni composites could be significantly improved by selecting appropriate carbon matrix precursors according to the features of specific reactions.