高温催化燃烧技术及其核心催化剂的研制

高温催化燃烧技术作为一项环境友好的能源利用方式正得到世界各国的广泛重视 ,催化燃烧器设计与燃烧催化剂研制领域不断取得新进展 .本文通过考察负载型 Pd催化剂和烧绿石型复氧化物催化剂的物化特性与催化反应动力学特征 。

Synthesis of K-doped three-dimensionally ordered macroporous Mn_(0.5)Ce_(0.5)O_δ catalysts and their catalytic performance for soot oxidation

A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.

Effect of Doping Cerium in the Support of Catalyst Pd-Co/Cu-Co-Mn Mixed Oxides on the Oxidative Carbonylation of Phenol

Effect of doping cerium in the support on the catalytic activity and side product of the reaction in the oxidative carbonylation of phenol to diphenyl carbonate (DPC) over the catalyst Pd-Co/Cu-Co-Mn mixed oxides was studied. The specific surface areas, crystal phase, valency, and content of the element on the surface of the catalysts were determined, and the products were detected by gas chromatograph/mass spectrometry (GC-MS). It is found that the catalyst without Ce shows higher activity than that with Ce, and the yields of DPC for the two cata-lysts can reach 30% and 23%, respectively. However, doping cerium can prevent the formation of 2-hydroxyphenyl benzoate and p-bromophenyl phenyl carbonate.

Glycerol hydrogenolysis to n‐propanol over Zr‐Al composite oxide‐supported Pt catalysts

Zr‐Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios（2.5%Pt/ZrxAl（1–x）Oy） were synthesized by an impregnation method and used for the selective hydrogenolysis of glycerol to n‐propanol in an autoclave reactor. The catalysts were fully characterized by X‐ray powder diffrac‐tion, Brunauer‐Emmett‐Teller surface area analysis, CO chemisorption, H2 temperature‐ pro‐grammed reduction, pyridine‐infrared spectroscopy, and NH3‐temperature‐programmed desorp‐tion. The results revealed that the Zr/Al ratio on the support significantly affected the size of the platinum particles and the properties of the acid sites on the catalysts. The catalytic performance was well correlated with the acidic properties of the catalyst; specifically, more acid sites contrib‐uted to the conversion and strong acid sites with a specific intensity contributed to the deep dehy‐dration of glycerol to form n‐propanol. Among the tested catalysts, 2.5 wt% Pt/Zr（0.7）Al（0.3）Oy exhibited excellent selectivity for n‐propanol with 81.2% glycerol conversion at 240 °C and 6.0 MPa H2 pres‐sure when 10% aqueous glycerol solution was used as the substrate. In addition, the effect of vari‐ous reaction parameters, such as H2 content, reaction temperature, reaction time, and number of experimental cycles were studied to determine the optimized reaction conditions and to evaluate the stability of the catalyst.

Support effect of zinc tin oxide on gold catalyst for CO oxidation reaction

Nanostructured gold catalyst supported on metal oxide is highly active for the CO oxidation reac‐tion. In this work, a new type of oxide support, zinc tin oxide, has been used to deposit 0.7 wt%Au via a deposition‐precipitation method. The textural properties of Zn2SnO4 support have been tuned by varying the molar ratio between base （N2H4＆#183;H2O） and metal ion （Zn2＋） to be 4/1, 8/1 and 16/1. The catalytic tests for CO oxidation reaction revealed that the reactivity on Au‐Zn2SnO4 with N2H4＆#183;H2O/Zn2＋ = 8/1 was the highest, while the reactivity on Au‐Zn2SnO4 with N2H4＆#183;H2O/Zn2＋ =16/1 was almost identical to that of the pure support. Both fresh and used catalysts have been characterized by multiple techniques including nitrogen adsorption‐desorption, X‐ray diffraction, transmission electron microscopy, high‐angle annular dark‐field scanning transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray adsorption fine structure, and tempera‐ture‐programmed reduction by hydrogen. These demonstrated that the textural properties, espe‐cially pore volume and pore size distribution, of Zn2SnO4 play crucial roles in the averaged size of gold nanoparticles, and thus determine the catalytic activity of Au‐Zn2SnO4 for CO oxidation.