In this paper, the Cu and ZnO nanoparticles were mixed by the ultrasonic dispersion method. The catalysts were used for dehydrogenation of 2-butanol. Comparing to the Cu and ZnO catalysts, the Cu-ZnO catalyst showed a...In this paper, the Cu and ZnO nanoparticles were mixed by the ultrasonic dispersion method. The catalysts were used for dehydrogenation of 2-butanol. Comparing to the Cu and ZnO catalysts, the Cu-ZnO catalyst showed a high catalytic activity and stability. The fresh and reacted catalysts were characterized by XRD, BET and EPR, which showed that the nano-scaled Cu and ZnO catalysts were deactivated during the reaction because of sintering and carbon deposition, respectively. In Cu-ZnO catalyst, the gathering of Cu particles was restrained by adding ZnO, and carbon deposition was avoided due to some interactions between Cu and ZnO.展开更多
Pd-Ag/ceramic composite membrane, which was prepared by improved electroless plating with osmosis , exhibited higher hydrogen flux,reaching 0.619 mol·s -1 ·m -2 (673 K,Δ p =0.196 MPa). The catalytic dehydro...Pd-Ag/ceramic composite membrane, which was prepared by improved electroless plating with osmosis , exhibited higher hydrogen flux,reaching 0.619 mol·s -1 ·m -2 (673 K,Δ p =0.196 MPa). The catalytic dehydrogenation of isobutane in the Pd-Ag/ceramic composite membrane reactor was studied. The effects of various operating parameters,such as reaction temperature, linear velocity of feed gas, linear velocity of purge gas, molar ratio of nitrogen to isobutane in feed gas, and pressure of feed gas on conversion of isobutane were investigated. It was observed that the conversion of isobutane (50.5% at 723 K) in the membrane reactor exceeded the equilibrium conversion (18.8% at 723 K) and that in the fixed-bed reactor (15.5% at 723 K). From experimental results for dehydrogenation of isobutane in the membrane reactor, it was found that when a certain partial pressure of hydrogen was maintained in the reaction-side of the reactor, the formation of accumulative carbon overlayers on the surface of dehydrogenation catalyst and membrane was inhibited to some extent, which reduced the deactivation rate of catalyst and membrane.展开更多
Pd-supported ZSM-5 zeolites prepared through ion exchange technique were used as a dehydrogenation catalyst for synthesis of o-phenylphenol from cyclohexanone. When Si/Al ratio in the catalyst was 85∶1 or more, an ob...Pd-supported ZSM-5 zeolites prepared through ion exchange technique were used as a dehydrogenation catalyst for synthesis of o-phenylphenol from cyclohexanone. When Si/Al ratio in the catalyst was 85∶1 or more, an obvious reduction in attenuation rate of catalyst activity was observed. When the Si/Al ratio was of 17∶1 or less, polymer compounds could be formed on the surface of zeolite, that would decrease the dehydrogenation activity due to the reduction of the specific surface area of the catalyst.展开更多
采用液相反应,以甲酸铜-甲酸镍为催化剂,将工业双戊烯催化脱氢合成对伞花烃。考察了催化剂制备条件如活性组分前体类型及其预处理方式、沉淀方法、载体加入顺序、铜镍摩尔比以及反应条件对产物中对伞花烃质量分数的影响,催化剂较佳合成...采用液相反应,以甲酸铜-甲酸镍为催化剂,将工业双戊烯催化脱氢合成对伞花烃。考察了催化剂制备条件如活性组分前体类型及其预处理方式、沉淀方法、载体加入顺序、铜镍摩尔比以及反应条件对产物中对伞花烃质量分数的影响,催化剂较佳合成条件为:以甲酸铜-甲酸镍为活性前体,采用并流沉淀的方法,碳酸钠溶液为沉淀剂,沉淀过程中加入载体活性炭,活性前体用无水乙醇洗涤,n(Cu^(2+)):n(Ni^(2+))=1:3。最佳合成条件为:采用液相反应,在180℃反应6 h,催化剂用量每15 mL 原料1.0 g,产物中对伞花烃的质量分数可达84.52%。展开更多
文摘In this paper, the Cu and ZnO nanoparticles were mixed by the ultrasonic dispersion method. The catalysts were used for dehydrogenation of 2-butanol. Comparing to the Cu and ZnO catalysts, the Cu-ZnO catalyst showed a high catalytic activity and stability. The fresh and reacted catalysts were characterized by XRD, BET and EPR, which showed that the nano-scaled Cu and ZnO catalysts were deactivated during the reaction because of sintering and carbon deposition, respectively. In Cu-ZnO catalyst, the gathering of Cu particles was restrained by adding ZnO, and carbon deposition was avoided due to some interactions between Cu and ZnO.
文摘Pd-Ag/ceramic composite membrane, which was prepared by improved electroless plating with osmosis , exhibited higher hydrogen flux,reaching 0.619 mol·s -1 ·m -2 (673 K,Δ p =0.196 MPa). The catalytic dehydrogenation of isobutane in the Pd-Ag/ceramic composite membrane reactor was studied. The effects of various operating parameters,such as reaction temperature, linear velocity of feed gas, linear velocity of purge gas, molar ratio of nitrogen to isobutane in feed gas, and pressure of feed gas on conversion of isobutane were investigated. It was observed that the conversion of isobutane (50.5% at 723 K) in the membrane reactor exceeded the equilibrium conversion (18.8% at 723 K) and that in the fixed-bed reactor (15.5% at 723 K). From experimental results for dehydrogenation of isobutane in the membrane reactor, it was found that when a certain partial pressure of hydrogen was maintained in the reaction-side of the reactor, the formation of accumulative carbon overlayers on the surface of dehydrogenation catalyst and membrane was inhibited to some extent, which reduced the deactivation rate of catalyst and membrane.
文摘Pd-supported ZSM-5 zeolites prepared through ion exchange technique were used as a dehydrogenation catalyst for synthesis of o-phenylphenol from cyclohexanone. When Si/Al ratio in the catalyst was 85∶1 or more, an obvious reduction in attenuation rate of catalyst activity was observed. When the Si/Al ratio was of 17∶1 or less, polymer compounds could be formed on the surface of zeolite, that would decrease the dehydrogenation activity due to the reduction of the specific surface area of the catalyst.
文摘相较于Wacker工艺进行乙醛工业化生产,发展多相催化体系实现乙醇直接无氧催化脱氢制乙醛和副产氢气,从生产工艺和经济价值方面无疑是一条更加安全高效的路线.在此,我们发展了一种高效、稳固的Cu/SiO2催化剂,用于乙醇的无受体催化脱氢.通过氨蒸发法制备得到高度分散的Cu颗粒,在没有任何平衡气体的纯乙醇进料条件下,显示出超强的热稳定性.活性组分Cu和载体SiO2之间的强相互作用,使其具有优异的催化性能.通过反应条件优化,在250℃下实现了较高的乙醇转化率(>40%)和乙醛选择性(>95%),且催化剂在固定床连续反应过程中可稳定运行超过400 h.
文摘采用液相反应,以甲酸铜-甲酸镍为催化剂,将工业双戊烯催化脱氢合成对伞花烃。考察了催化剂制备条件如活性组分前体类型及其预处理方式、沉淀方法、载体加入顺序、铜镍摩尔比以及反应条件对产物中对伞花烃质量分数的影响,催化剂较佳合成条件为:以甲酸铜-甲酸镍为活性前体,采用并流沉淀的方法,碳酸钠溶液为沉淀剂,沉淀过程中加入载体活性炭,活性前体用无水乙醇洗涤,n(Cu^(2+)):n(Ni^(2+))=1:3。最佳合成条件为:采用液相反应,在180℃反应6 h,催化剂用量每15 mL 原料1.0 g,产物中对伞花烃的质量分数可达84.52%。
