The CO2reforming of CH4is studied over MgO‐promoted Ni catalysts,which were supported on alumina prepared from hydrotalcite.This presents an improved stability compared with non‐promoted catalysts.The introduction o...The CO2reforming of CH4is studied over MgO‐promoted Ni catalysts,which were supported on alumina prepared from hydrotalcite.This presents an improved stability compared with non‐promoted catalysts.The introduction of the MgO promoter was achieved through the‘‘memory effect’’of the Ni‐Al hydrotalcite structure,and ICP‐MS confirmed that only0.42wt.%of Mg2+ions were added into the Ni‐Mg/Al catalyst.Although no differences in the Ni particle size and basicity strength were observed,the Ni‐Mg/Al catalyst showed a higher catalytic stability than the Ni/Al catalyst.A series of surface reaction experiments were used and showed that the addition of a MgO promoter with low concentration can promote CO2dissociation to form active surface oxygen arising from the formation of the Ni‐MgO interface sites.Therefore,the carbon‐resistance promotion by nature was suggested to contribute to an oxidative environment around Ni particles,which would increase the conversion of carbon residues from CH4cracking to yield CO on the Ni metal surface.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.展开更多
Carbon black-phenolic resin composite binders with various amounts of nanoscale carbon black were pre pared through adding KH 550 coupling agent and high-speed mixer. The effects of nanoscale carbon black amount added...Carbon black-phenolic resin composite binders with various amounts of nanoscale carbon black were pre pared through adding KH 550 coupling agent and high-speed mixer. The effects of nanoscale carbon black amount added on viscosity of the composite binders were studied. Low-carbon MgO-C specimens were fabricated with these composite binders. Effects of nanoscale carbon black contents （0, 2.5%, 5%, 10%, and 15% of phenolic resin in mass percent） on mechanical properties of low-carbon MgO-C specimens were investigated. The results revealed that the viscosity of the composite binder increased rapidly with increase of nanoscale carbon black content, and that CMOR, HMOR （high modulus of rupture） and CCS （cold crushing strength） of the specimens increased gradually with increase of nanoscale carbon black content as well.展开更多
B4C was added into the low-carbon MgO-C materials in order to improve the oxidation resistance. The results show adding 0. 3wt% B4C can get the best oxidation resistance and adding 0. 2 wt% B4C can get the highest hot...B4C was added into the low-carbon MgO-C materials in order to improve the oxidation resistance. The results show adding 0. 3wt% B4C can get the best oxidation resistance and adding 0. 2 wt% B4C can get the highest hot modulus of rupture. Altogether, adding 0. 2wt% B,C into the low-carbon MgO-C materials can get better oxidation resistance and hot strength.展开更多
The effect of Ti （ C, N） on properties of low-carbon MgO - C bricks was investigated. The phase composition and the microstructure of the matrix of low-carbon MgO - C brick containing Ti （ C, N） were studied by XR...The effect of Ti （ C, N） on properties of low-carbon MgO - C bricks was investigated. The phase composition and the microstructure of the matrix of low-carbon MgO - C brick containing Ti （ C, N） were studied by XRD and SEM analysis together with EDS. The results showed that Ti （ C, N） distributed in the matrix of lowcarbon MgO - C brick uniformly after being treated at 1 600 ~C for 3 h in coke powder bed, and Ti （C, N） and MgO formed a solid solution. After the treatment at 1 600 ℃ for 3 h in coke powder bed, the bulk density and cold crushing strength of low-carbon MgO - C brick with Ti （ C, N） decreased, and the apparent porosity and linear change rate of specimens increased. The oxidation resistance of low-carbon MgO - C brick with Ti（ C, N） was superior to that of low-carbon MgO - C brick with no additives, but inferior to that of low-car- bon MgO - C brick with Al powder. The slag resistance of the specimen with Ti （ C, N） was excellent as well.展开更多
基金supported by the National Natural Science Fundation of China(U1361202,51276120)~~
文摘The CO2reforming of CH4is studied over MgO‐promoted Ni catalysts,which were supported on alumina prepared from hydrotalcite.This presents an improved stability compared with non‐promoted catalysts.The introduction of the MgO promoter was achieved through the‘‘memory effect’’of the Ni‐Al hydrotalcite structure,and ICP‐MS confirmed that only0.42wt.%of Mg2+ions were added into the Ni‐Mg/Al catalyst.Although no differences in the Ni particle size and basicity strength were observed,the Ni‐Mg/Al catalyst showed a higher catalytic stability than the Ni/Al catalyst.A series of surface reaction experiments were used and showed that the addition of a MgO promoter with low concentration can promote CO2dissociation to form active surface oxygen arising from the formation of the Ni‐MgO interface sites.Therefore,the carbon‐resistance promotion by nature was suggested to contribute to an oxidative environment around Ni particles,which would increase the conversion of carbon residues from CH4cracking to yield CO on the Ni metal surface.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.
文摘Carbon black-phenolic resin composite binders with various amounts of nanoscale carbon black were pre pared through adding KH 550 coupling agent and high-speed mixer. The effects of nanoscale carbon black amount added on viscosity of the composite binders were studied. Low-carbon MgO-C specimens were fabricated with these composite binders. Effects of nanoscale carbon black contents （0, 2.5%, 5%, 10%, and 15% of phenolic resin in mass percent） on mechanical properties of low-carbon MgO-C specimens were investigated. The results revealed that the viscosity of the composite binder increased rapidly with increase of nanoscale carbon black content, and that CMOR, HMOR （high modulus of rupture） and CCS （cold crushing strength） of the specimens increased gradually with increase of nanoscale carbon black content as well.
文摘B4C was added into the low-carbon MgO-C materials in order to improve the oxidation resistance. The results show adding 0. 3wt% B4C can get the best oxidation resistance and adding 0. 2 wt% B4C can get the highest hot modulus of rupture. Altogether, adding 0. 2wt% B,C into the low-carbon MgO-C materials can get better oxidation resistance and hot strength.
文摘The effect of Ti （ C, N） on properties of low-carbon MgO - C bricks was investigated. The phase composition and the microstructure of the matrix of low-carbon MgO - C brick containing Ti （ C, N） were studied by XRD and SEM analysis together with EDS. The results showed that Ti （ C, N） distributed in the matrix of lowcarbon MgO - C brick uniformly after being treated at 1 600 ~C for 3 h in coke powder bed, and Ti （C, N） and MgO formed a solid solution. After the treatment at 1 600 ℃ for 3 h in coke powder bed, the bulk density and cold crushing strength of low-carbon MgO - C brick with Ti （ C, N） decreased, and the apparent porosity and linear change rate of specimens increased. The oxidation resistance of low-carbon MgO - C brick with Ti（ C, N） was superior to that of low-carbon MgO - C brick with no additives, but inferior to that of low-car- bon MgO - C brick with Al powder. The slag resistance of the specimen with Ti （ C, N） was excellent as well.
