A novel K2O and La2O3 promoted nickel catalyst supported on a-Al2O3 was prepared by co-impregnation method, and it exhibited higher activity and 6-aminocapronitrile selectivity than Ni/a-Al2O3 during the hydrogenation...A novel K2O and La2O3 promoted nickel catalyst supported on a-Al2O3 was prepared by co-impregnation method, and it exhibited higher activity and 6-aminocapronitrile selectivity than Ni/a-Al2O3 during the hydrogenation of adiponitrile in the absence of ammonia, i.e., K2O and La2O3 improved the performance of the nickel-based catalyst.展开更多
The reaction mechanism of the liquid phase ammoniation of adipic acid to adiponitrile was studied experimentally in a semi-batch reactor. Macrokinetics of the main and side reactions were identified to minimize corros...The reaction mechanism of the liquid phase ammoniation of adipic acid to adiponitrile was studied experimentally in a semi-batch reactor. Macrokinetics of the main and side reactions were identified to minimize corrosion and coking to prolong the operation period, to increase the yield of adiponitrile and to improve the design of the reactor. Macrokinetic equations of ammoniation-neutralization of adipic acid and dehydration were of first-order to adipic concentration cB≥3.5% and of second order for cB≥3.5%. Catalyst H3PO4 reduced the activation energy of neutralization and dehydration reactions of adipic acid and was significantly important for the second step of dehydration to produce adiponitrile.展开更多
A Ni-RE-P-Al catalyst prepared by alkaline extraction of a rapidly quenched Ni-RE-P-Al alloy was characterized by means of ICP, BET, XRD, XPS and TEM. The results show that the rapidly quenched Ni-RE-P-Al alloy conta...A Ni-RE-P-Al catalyst prepared by alkaline extraction of a rapidly quenched Ni-RE-P-Al alloy was characterized by means of ICP, BET, XRD, XPS and TEM. The results show that the rapidly quenched Ni-RE-P-Al alloy contained less crystalline Al_3Ni than Al-Ni alloy. After alkaline extraction, most of Al in the Ni-RE-P-Al alloy was leached out and the resulted Ni-RE-P-Al catalyst presented a sponge structure similar to Raney Ni. Although crystalline Ni is the major phase in the Ni-RE-P-Al catalyst and Raney Ni, amorphous Ni-P phase has been detected in the Ni-RE-P-Al catalyst. Studies on catalytic hydrogenation of toluene, phenyl ethylene, acetylene benzene, nitrobenzene, cyclohexanone and adiponitrile in liquid phase showed that the activity and selectivity of this Ni-RE-P-Al catalyst are superior to those of Raney Ni, especially at low temperatures. The amorphous phase is considered to be responsible for its superior catalytic properties.展开更多
文摘A novel K2O and La2O3 promoted nickel catalyst supported on a-Al2O3 was prepared by co-impregnation method, and it exhibited higher activity and 6-aminocapronitrile selectivity than Ni/a-Al2O3 during the hydrogenation of adiponitrile in the absence of ammonia, i.e., K2O and La2O3 improved the performance of the nickel-based catalyst.
文摘The reaction mechanism of the liquid phase ammoniation of adipic acid to adiponitrile was studied experimentally in a semi-batch reactor. Macrokinetics of the main and side reactions were identified to minimize corrosion and coking to prolong the operation period, to increase the yield of adiponitrile and to improve the design of the reactor. Macrokinetic equations of ammoniation-neutralization of adipic acid and dehydration were of first-order to adipic concentration cB≥3.5% and of second order for cB≥3.5%. Catalyst H3PO4 reduced the activation energy of neutralization and dehydration reactions of adipic acid and was significantly important for the second step of dehydration to produce adiponitrile.
基金the National Natural Science Foundation of China.
文摘A Ni-RE-P-Al catalyst prepared by alkaline extraction of a rapidly quenched Ni-RE-P-Al alloy was characterized by means of ICP, BET, XRD, XPS and TEM. The results show that the rapidly quenched Ni-RE-P-Al alloy contained less crystalline Al_3Ni than Al-Ni alloy. After alkaline extraction, most of Al in the Ni-RE-P-Al alloy was leached out and the resulted Ni-RE-P-Al catalyst presented a sponge structure similar to Raney Ni. Although crystalline Ni is the major phase in the Ni-RE-P-Al catalyst and Raney Ni, amorphous Ni-P phase has been detected in the Ni-RE-P-Al catalyst. Studies on catalytic hydrogenation of toluene, phenyl ethylene, acetylene benzene, nitrobenzene, cyclohexanone and adiponitrile in liquid phase showed that the activity and selectivity of this Ni-RE-P-Al catalyst are superior to those of Raney Ni, especially at low temperatures. The amorphous phase is considered to be responsible for its superior catalytic properties.
