Yang Weishen

Surface structure and catalytic performance of supported PtSn catalysts

The valence states of tin in supported PtSn catalysts after reduction were tracked by in situ Mössbauer spectroscopy. Combined with catalytic evaluation, it is suggested that only when tin is in oxidative states, the catalytic performance can be greatly improved. The changes of surface structure of PtSn/Al2O3 during repeated coking-regeneration-reduction (CRR) cycles were also studied.

Oxygen Permeating Properties of the Mixed Conducting Membranes without Cobalt

A new series of mixed conducting oxides, Sr10-n/2BinFe20Om (n = 4, 6, 8, 10), were synthesized by a solid state reaction method, and they have high oxygen permeability. The oxygen permeation rate at 1150 K is 0.41 ml(STD)/ cm(2).min for n = 6 and 0.90 ml(STD)/cm(2).min for n = 10, which is two times higher than that for Sr1-xBixFeO3 (x = 0.5). For the Sr1-xBixFeO3 (x = 0.1, 0.3, 0.5) series, the oxygen flux increases with increasing Bi content

Interaction of NiO with γ-Al 2 O 3 Supporter of NiO/γ-Al 2 O 3 Catalysts

利用溶胶－凝胶法制备了不同含量的ＮｉＯ／γ－Ａｌ２Ｏ３催化剂，通过ＸＲＤ，ＸＰＳ和ＴＰＲ等技术考察了制备方法，ＮｉＯ含量和焙烧温度对催化剂结构和Ｎｉ存在状态的影响，发现溶胶－凝胶法制备的催化剂活性组分ＮｉＯ与担体γ－Ａｌ２Ｏ３间具有强相互作用。

Influence of the Reducing Atmosphere on the Structure and Activity of Mo-V-Te-Nb-O Catalysts for Propane Selective Oxidation

The effects of the addition of the reductant (ammonium chloride) on Mo-V-Te-Nb-O mixed oxide catalysts for propane selective oxidation to acrylic acid were systematically investigated. The presence of the reductant during catalyst preparation had a significant impact on the mobility of lattice oxygen mainly responsible for the catalytic activity of the Mo-V-Te-Nb-O catalysts. Furthermore, the addition of the reductant resulted in clear changes in catalyst morphology and phase composition, which are important factors in the formation of acrylic acid. A high content of the orthorhombic M1 phase led to a high selectivity to acrylic acid at low temperatures ( 653 K).

Hydrogen Permeation in a Thin Pd-Cu Alloy Membrane Reactor for Steam Reforming of Ethanol

Hydrogen permeation through a thin fcc-pd(0.9)cu(0.1) alloy composite membrane was investigated with h(2)-ar-c(2)h(5)oh- h(2)o mixtures for this modeling reaction over a range of temperature (250-500 degrees c) and pressure (160-310 kpa) the influence of temperature, feed pressure. feed flow rate, ratio of ethanol to steam, and hydrogen concentration of feed was examined under the operating conditions ethanol has inhibitive effect on hydrogen permeation performance through the membrane in comparison with that in pure hydrogen atmosphere. moreover, hydrogen flux increased with mereasing total mixture pressure and hydrogen concentration in the mixture feed but was not related to the ratio of ethanol to steam thus, the inhibitive influence of ethanol on hydrogen permeation was similar to that of steam under the same operating conditions although ethanol and steam can decrease hydrogen permeation, the hydrogen flux of membrane up to 11 3 m(3)/(m(2) h) and hydrogen recovery over 62.5% were obtained in h(2)-ar-c(2)h(5)oh-h(2)o (h(2) ar (c(2)h(5)oh h(2)o) volume ratio = 60 30 10) mixtures at 500 c and 310 kpa the membrane was stable without poisoning under ethanol-containing mixtures and would be suitable for the catalytic membrane reactor of steam reforming of ethanol to pure hydrogen production