Graphene-like wrapped Ni@C catalyst with magnetic recyclability for selective hydrogenation of nitro-aromatics.

The graphene-like wrapped Ni@C catalysts were facilely synthesized by a modified sol-gel method. Nickel nitrate and citric acid (CA) were adopted as the raw materials to form sol-gel mixture. Under the circumstances, the additive CA were employed not only as a complexing agent but also as a carbon source. It is found that the calcination temperature and the mole ratios between Ni and CA are the key factors affecting the physical property and the catalytic performance of catalysts in the conversion of nitroarenes into corresponding anilines. The results show that the Ni@C-500(1:1) catalyst exhibited the best performance in the hydrogenation ofo-chloronitrobenzenes (o-CNB) too-chloroanilines (o-CAN). The yield ofo-CAN was achieved at 100% wheno-CNB was completely converted at 40.0 °C under 2.0 MPa H2for 2.0 h. Furthermore, the Ni@C-500(1:1) catalyst could be separated and recovered easily after reaction by an external magnetic field. The investigated results indicate that the Ni@C-500(1:1) catalyst remained higher activity after using twelve times. More importantly, this kind of catalyst is also active for the selective hydrogenation of other nitroarenes into the corresponding anilines. This new synthetic method may pave a way for producing low-cost Ni@C catalysts on a large scale, which is attractive for industrial anilines applications.

High efficient conversion of CO2-rich bio-syngas to CO-rich bio-syngas using biomass char: a useful approach for production of bio-methanol from bio-oil.

A novel approach for high efficient conversion of the CO(2)-rich bio-syngas into the CO-rich bio-syngas was carried out by using biomass char and Ni/Al(2)O(3) catalyst, which was successfully applied for production of bio-methanol from bio-oil. After the bio-syngas conditioning, the CO(2)/CO ratio prominently dropped from 6.33 to 0.01-0.28. The maximum CO yield in the bio-syngas conditioning process reached about 1.96 mol/(mol CO(2)) with a nearly complete conversion of CO(2) (99.5%). The performance of bio-methanol synthesis was significantly improved via the conditioned bio-syngas, giving a maximum methanol yield of 1.32 kg/(kg(catalyst)h) with a methanol selectivity of 99%. Main reaction paths involved in the bio-syngas conditioning process have been investigated in detail by using different model mixture gases and different carbon sources.