The Effect of Nb Loading on Catalytic Properties of Ni/Ce0.75Zr0.25O2 Catalyst for Methane Partial Oxidation

In this study,the effect of Nb loading on the catalytic activity of Ce_(0.75)Zr_(0.25)O_2-supported Ni catalysts was studied for methane partial oxidation.The catalysts were characterized by BET,H_2 chemisorption,XRD,TPR,TEM and tested for methane partial oxidation to syngas in the temperature range of 400-800℃at atmospheric pressure.The results showed that the activity of methane partial oxidation on the catalysts was apparently dependent on Nb loading.It seemed that the addition of Nb lowered the catalytic activity for methane partial oxidation and increased the extent of carbon deposition. This might be due to the strong interaction between NiO and Nb-modified support and reduction of surface oxygen reducibility.     

电子受体H2O2和O2对TiO2光催化甘油氧化反应中活性氧物种1O2和OH?的影响

在室温条件下研究了电子受体H2O2和O2对TiO2光催化甘油氧化反应中的活性氧物种、甘油转化率和产物分布的影响。当在紫外光辐射和TiO2的体系中不存在电子受体时,只产生HO?自由基。而当在此体系中有电子受体存在时,则产生了HO?自由基和1O2,但它们的浓度不同,这取决于电子受体的浓度。以H2O2为电子受体时甘油转化率的提高大于以O2为电子受体时。甘油转化生成有价值产物的类型则与体系中的活性氧物种浓度有关。     

The H2S decomposition activity of supported MoS2 catalysts prepared via PFHS method

Silica-supported MoS₂ catalysts prepared via precipitation from homogeneous solution (PFHS) exhibited high surface areas (180–190 m² g^–1 and activities which were about twice those of the unsupported specimens. An 8% Mo catalyst showed optimum activity. The superior activity of the supported specimen was attributed to the higher population of active sites occasioned by the good dispersion during PFHS. TEM examination also confirmed the existence of small MoS₂ crystallites on the silica support.