<正>随着社会的发展,人类对能源的需求越来越多,但是地球上化石资源的储藏量逐渐减少,不可再生资源正面临枯竭,对人类的生存提出了挑战,寻找开发新型能源已迫在眉睫.众所周知,绿色化学[1-2]代表了当今化学工业的发展方向;绿色化学希望化合物的来源是绿色的,即源于那些可再生资源;其生产工艺环境友好,采用无毒无害的原料和

The oxidation of cellulose to oxycellulose by sodium periodate was studied.The generation of oxycellulose was confirmed with Fourier transform infrared spectra(FTIR) analysis;the contrasts of cellulose structure before and after reaction were conducted by Scanning electron microscope(SEM),thermogravimetry-differential scanning calorimetry(TG-DSC) and X-ray diffractometer(XRD).The effects of reaction conditions such as oxidation time,temperature,oxidant concentration and pH value of solution on the yield and content of aldehyde group in the oxycellulose were investigated in detail.The results indicated that the crystalline form and surface morphology of cellulose had almost no change before and after reaction;the thermal stability of oxycellulose became weaker when the oxidation degree was deeper;and that when NaIO4 concentration and oxidation temperature increased,the aldehyde group content increased also;whereas it could reach higher value at optimum pH value and oxidation time.

Methanol synthesis from hydrogénation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M(Cu, Zn)-ammonia complexes (DMAC) at various temperatures. The catalysts were characterized in detail, including X-ray diffraction, N2 adsorption-desorption, N2O chemisorption, temperature-programmed reduction and evolved gas analyses. The influences of DMAC temperature, reaction temperature and specific Cu surface area on catalytic performance are investigated. It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts. The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol (212 g/(Lcat · h); T = 513 K, p = 3 MPa, SV = 12000 h−1).

Cu/ZnO/Al2O3 catalyst was prepared by coprecipition-amonia evaporation(CAE) method using ammonium carbonate as precipitating agent.The reference catalysts were prepared by conventional coprecipitation using ammonium carbonate(CCA) and sodium carbonate(CCS) as precipitating agents.XRD,BET,TPR and N2O titration technology were employed to investigate the structure and surface performance of the catalysts.The CAE-derived catalyst showed relatively smaller particle size and higher specific Cu(0) surface area.The CCA-derived catalyst displayed the highest total surface area,but the specific Cu(0) surface area was relatively lower.The residual Na+ was more difficult to be removed than NH4+,and facilely led to the agglomeration of Cu resulting in the lower specific Cu(0) surface area.The catalytic performance of CAE catalyst was better than others,resulting from the higher specific Cu(0) surface area.

A Cu/ZnO/Al2O3 catalyst prepared by adding CO2 during the aging step was used for methanol synthesis from CO2 and H2. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction, field emission scanning electron microscope, temperature-programmed decomposition, and temperature-programmed reduction. The precursor from the modified method with added CO2 had malachite and hydrotalcite-like phases and was more stable than that of the sample without added CO2. After calcination, the modified catalyst had a higher surface area, larger pore volume, and smaller particle size. The modified catalyst gave a higher activity for methanol synthesis from CO2 hydrogenation in the reaction temperature range of 200–260 oC.

采用共沉淀法制备了一系列催化剂,并利用XRD,XPS对催化剂结构进行了表征,考察了铜掺杂量,焙烧温度,空速以及CO 2 和H 2 O的存在对选择氧化消除CO反应的影响。结果表明,在600℃焙烧后的催化剂具有最佳的催化活性和选择性,而且在CO 2 和H 2 O的存在下140℃也能达到有效消除CO（100 ppm以下）的目的,同时选择性可达到了70．1%。100h的连续测试显示,催化剂具有良好的稳定性。

A series of CuO/Ce0.9Zr0.1O2 catalysts for CO oxidation were prepared by precipitation method.X-ray diffraction pattern,XPS analyses were used for characterization of the catalysts.The effects of catalysts calcination temperature,CuO contents,GHSV,presence of CO2 and H2O on the selective oxidation of CO over the catalysts were investigated,and exhibited very high catalytic performance over the 7% CuO Ce0.9Zr0.1O2 catalyst when calcinations temperature at 600 ℃,with 99.5% conversion of CO and 70% selectivity at 140 ℃.And also,very good catalytic stability was obtained for 100 h continuous evaluation.

A urea combustion method was used for the preparation of the Cu–Ce–O catalyst without the need for a binder or additional calcination steps. The catalytic performance of the catalyst for preferential oxidation of CO was investigated under dry and humid feed gas conditions, and the catalyst was also examined for CO removal at the operating temperature of the PEMFC anode. A 99.3% CO conversion and 75% selectivity for CO2 could be achieved at 130°C in the presence of H2O and CO2. The results of XRD and SEM characterizations indicated that copper oxides were highly dispersed on the catalyst and formed nanoparticles.