溶胶-凝胶法制备用于CO2气氛下乙苯脱氢反应的高活性Cr2O3-SiO2催化剂

 采用溶胶-凝胶法制备了Cr2O3-SiO2催化剂，考察了催化剂对CO2气氛下乙苯脱氢制苯乙烯反应的催化性能. 结果表明，溶胶-凝胶法制备的Cr2O3-SiO2催化剂上乙苯脱氢活性是常规的Cr2O3/SiO2负载型催化剂的2倍，Cr2O3-SiO2催化剂中Cr6+的含量较高是其具有高活性的主要原因.     

TG Measurements of the Oxidation Kinetics of Fe-Cr Alloy with Regard to its Application as a Separator in SOFC

The high-temperature oxidation behavior of a ferritic alloy (SUS 430) in a SOFC environment, corresponding to the anode (H₂/H₂O gas mixture) and cathode (air) operating conditions, was determined with regard to application of the alloy as a metallic separator material in SOFC. The oxidation kinetics of Fe-16Cr alloy (SUS 430), was studied by thermogravimetry in H₂/H₂O gas mixtures with p_H/p_HO=94/6 and 97/3 and in air, in the temperature range 1023-1223 K, for 3.6 up to 1080 ks. It was found that the protective oxide scale, composed mainly of Cr₂O₃ with uniform thickness and excellent adhesion to the metal substrate, grows in accordance with the parabolic rate law. The dependence of the parabolic rate constant, k_p, of the scale on temperature obeys the Arrhenius equation: k_p=6.8×10^-4 exp (-202.3 kJ mol^-1R^-1T^-1) for H₂/H₂O gas mixtures with p_H/p_HO=94/6. The determined k_p was independent of the oxygen partial pressure in the range from 5.2×10^-22 to 0.21 atm at 1073 K, which means that the rates of growth of the scale on Fe-16Cr alloy in the above-mentioned atmospheres are comparable. The oxidation test results on Fe-16Cr alloy in H₂/H₂O gas mixtures and air demonstrate the applicability of SUS 430 alloys as a separator for SOFC. This revised version was published online in July 2006 with corrections to the Cover Date.     

CrOx/SiO2催化剂对C10+芳烃加氢脱烷基反应的催化性能

 采用等体积浸渍法制备了一系列不同组成的CrOx/SiO2催化剂样品,并用XRD,FT-IR,UV-Vis,TPR和N2吸附等技术对催化剂样品进行了表征,考察了催化剂对C10+重芳烃加氢脱烷基反应的催化性能. 结果表明,CrOx/SiO2催化剂对C10+重芳烃加氢脱烷基反应的催化性能与催化剂的表面结构有关,脱烷基活性主要来自载体表面的CrOx物种. 当催化剂中n(Cr)/n(Si)=1%～2%时,CrOx在SiO2表面达到单层分散; 当n(Cr)/n(Si)=2%～20%时,表面CrOx物种含量的变化不大,催化剂的活性及选择性基本不变.