Different potassium permanganate oxidation processes were used to modify activated carbon, and then surface structure and chemical properties of modified activated carbon with different preparation methods as well as their influences on carbon dioxide reforming of methane were studied. BET and SEM surface structure analysis indicated that after modification with potassium permanganate under alkaline condition, specific surface area of activated carbon increased, microspore and mesoporous capacities enlarged, but the pore diameter of activated carbon slightly reduced. XPS and FT-IR characterization indicated that after modification with potassium permanganate under alkaline condition, acid oxygen-containing functional groups dropped and new alkaline active substances like ionic OH− and manganite were generated on the activated carbon surface. Increased specific surface area and pore capacity of activated carbon, reduced acid oxygen-containing groups and generated alkaline active substances like ionic OH− and manganite exerted significant influences on methane activation and carbon dioxide reforming of methane. Under alkaline condition, the activity of the potassium permanganate modified activated carbon and reforming conversion slightly increased because of interaction between alkaline functional groups and acid carbon dioxide; In the meantime, newly generated ionic OH− on the surface and manganite participated in reforming reaction, which also improved activity of potassium permanganate-modified activated carbon for carbon dioxide reforming of methane. Under acid condition, CO2-CH4 reforming conversion and catalyst activity decreased because of interaction between acidic functional groups and acid carbon dioxide.

The activated carbon (AC) was modified by impregnation and impregnation-calcination methods using a series of agents to improve its surface property,and the surface functional groups and topography of AC were determined and characterized by Boehm titration and SEM techniques,respectively.The effects of modifying the AC on its catalytic performaces in carbon dioxide reforming of methane were investigated.The results show that the surfaces are acidic for the AC modified by HCl,H3PO4,AcOOH (C2H4O3) and NaClO,respectively,reducing catalytic activity;and the surfaces are alkline for the AC modified by NaOH,Na2CO3,NaHCO3,KMnO4 and HNO3,respectively,enhancing catalytic activity.The catalytic activity of various modified AC is in the following order:C2H4O3-AC ＜ NaClO-AC ＜ H3PO4-AC ＜ HCl-AC ＜ AC ＜ NaHCO3-AC ＜ Na2CO3-AC ＜ NaOH-AC ＜ KMnO4-AC ＜ HNO3-AC.The high activity of KMnO4-AC and HNO3-AC is attributed to incresed surface basic functional groups and well-developed porous structure.

The research progress of CO2 adsorption performance of solid porous materials such as zeolite,activated carbon,mesoporous silica material,metal-organic frameworks,is reviewed.The recent development of CO2 adsorption performance of hierarchical porous materials is also stated.The existing problems during CO2 adsorption capture are pointed out.The development trends of the carbon dioxide adsorbents in the future are also proposed.

Series of Co-Ni/activated carbon (AC) with different mass ratio of Co/Ni, Co-ZrO2/AC and Co-Ni-ZrO2/AC catalysts were prepared by co-impregnation, and characterized by XRD, SEM and BET. Their performances for carbon dioxide reforming of methane to syngas were investigated in a fixed bed reactor. The results show that the 8Co-4Ni-ZrO2/AC had larger surface area, smaller metal particles and better metal dispersion, exhibiting excellent catalytic activity and stability, which could obtain high methane and carbon dioxide conversions of both more than 95% under 850° C, and no obvious deactivation was observed in 1900 min.

炭材料是一种应用广泛的吸附剂和催化剂载体,其表面化学性质对炭材料性能影响重大.为了提高其吸附、催化等性能,需要对炭材料表面官能团进行调控.介绍了炭材料表面改性方法(氧化法、还原法),对工业、环境领域的应用进展进行了评述,并提出了炭材料改性技术的研究发展方向.

A mini coke oven has been used to study the shrinkage crack character in the process of semi-coke formation. The results show that the section of coke cake has been clearly layered, from the inner to outward, divided into loose honeycomb semi-coke layer, small honeycomb semi-coke layer, compact semi-coke layer, cracks layer. The colour of loose honeycomb semi-coke layer and small honeycomb semi-coke layer is dark black, and its porosity about 44.8%. The colour of the compact semi-coke layer is bright black, and its porosity about 34.0%. The colour of cracks layer is silver gray, and its porosity about 46.0%. The pyrolytic plastic layer area of static and dynamics state difference, the static state pyrolytic plastic layer area is an obturation flat elliptic area, wrapped in the middle of semi-coke; the dynamic state pyrolytic plastic layer area is a placket oblate gasbag, wrapped by semi-coke from the outside. The shrinkage rate of semi-coke increases with temperature increase, the relationship between shrinkage and temperature can be described as Y=-7x10(-5) + 0.14X-56.26 (600 degrees C-850 degrees C). The thickness of semi-coke decreases, with increasing temperature, crack increases and clump decreases. Add proper humidity to coal, the crack of semi-coke decreases and the clump increases.

利用固定床反应装置研究了催化剂Co/活性炭（AC）中引入助剂Mg O对甲烷二氧化碳重整制合成气催化剂性能的影响,并通过XRD、SEM和BET技术对催化剂进行了表征。结果表明,添加适量的助剂Mg O一方面与活性物质发生协同作用,提高催化剂的比表面积;另一方面可以调节催化剂的酸碱性,提高催化剂对CO2的吸附活化,从而促进甲烷的裂解脱氢。400℃焙烧条件下制备的催化剂Co-Mg O/AC表现出最佳的催化活性和稳定性,在900℃下连续运行1 200 min,甲烷和二氧化碳转化率分别维持在96.7%和97.0%左右。

In this paper, Datong coal-based activated carbon was selected as the main research object, and the research of the effects of the activated carbon modified by different concentrations of oxidant solution in dry methane reforming reaction were carried out, using potassium permanganate as an oxidant. The results show that methane and carbon dioxide conversion reached the maximum over 0.06 mol/L KMnO4 solution modified activated carbon. Compared with origin activated carbon, the largest degree of enhancement of CO2 conversion is at 750 degrees C. While the largest degree of enhancement of CH4 conversion is at 800 degrees C. At the same time, the yield of the CO increased over modified activated carbon. The modified activated carbon catalyst has the advantages of being high in catalyst activity, good in anti-carbon performance and stability. However, it was found that there is also water generation in reforming and the yield of hydrogen decrease.

An orthogonal experiment design was adopted for synthesis and optimization of ZrO2-Based catalyst for coke oven gas CO shift. The influence of the operating parameters on catalytic properties was investigated, with a composition being similar to typical industrial heterogeneous catalysts for WGS process. The experimental CO conversion data was analyzed by marginal and variance analysis. The optimal operating parameters for ZrO2-Al2O3 based catalyst were suggested by CO conversion.

A small-size gasification unit is improved through process optimization to simulate industrial United Gas Improvement Company gasification. It finds that the reaction temperature has important impacts on semicoke catalyzed methane gas mixture. The addition of water vapor can enhance the catalytic activity of reforming, which is due to the fact that addition of water vapor not only removes carbon deposit produced in the reforming and gasification reaction processes, but also participates in gasification reaction with semicoke to generate some active oxygen-containing functional groups. The active oxygen-containing functional groups provide active sites for carbon dioxide reforming of methane, promoting the reforming reaction. It also finds that the addition of different proportions of methane-rich gas can yield synthesis gas with different H 2 /CO ratio. The kinetics study shows that the semicoke can reduce the activation energy of the reforming reaction and promote the occurrence of the reforming reaction. The kinetics model of methane reforming under the conditions of steam gasification over semicoke is as follows:k-=5.02×103·pCH40.71·pH20.26·exp(−74200/ RT ).

BiOI flowerlike hierarchical structure was synthesized by the direct hydrolysis method - hydrolysis at room temperature in the presence of polyvinyl pyrrolidone. As-synthesized BiOI was characterized by powder X-ray diffraction, UV-vis diffuse reflectance spectra, X-ray photoelectron spectroscopy spectra, scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. It is a facile way to obtain BiOI flowerlike hierarchical structure photocatalyst for photocatalytic reduction of CO2 into hydrocarbon fuels under simulated sunlight irradiation without cocatalyst. And the photocatalytic activity of as-synthesized BiOI is higher than that of P25 TiO2 and bulk BiOI. (C) 2014 Elsevier Ltd. All rights reserved.

Syngas production by CO2 reforming of CH4 in a fixed bed reactor was investigated over a series of activated carbon (AC) supported Co catalysts as a function of Co loading (between 15 and 30wt.%) and calcination temperature (Tc=300, 400 or 500°C). The catalytic performance was assessed through CH4 and CO2 conversions and long-term stability. XRD and SEM were used to characterize the catalysts. It was found that the stability of Co/AC catalysts was strongly dependent on the Co loading and calcination temperature. For the loadings (25wt.% for Tc=300°C), stable activities have been achieved. The loading of excess Co (>wt.% 25) causes negative effects not only on the performance of the catalysts but also on the support surface properties. In addition, the experiment showed that ultrasound can enhance and promote dispersion of the active metal on the carrier, thus improving the catalytic performance of the catalyst. The catalyst activity can be long-term stably maintained, and no obvious deactivation has been observed in the first 2700min. After analyzing the characteristics, a reaction mechanism for CO2 reforming of CH4 over Co/AC catalyst was proposed.

In this paper, a fixed-bed reactor is used to study the influence of different conditions on carbon catalyzed CO2–CH4 reforming. The surface structure and functional groups of carbonaceous material have been characterized through SEM, XPS, XRD, BET and chemical titration before and after the reaction. Studies have revealed that under non-catalytic condition, methane pyrolysis happens first, followed by the gasification reaction between CO2 and carbon deposit produced from the pyrolysis. While with carbonaceous material, CO2 gasification, methane pyrolysis and CO2–CH4 reforming can take place at the same time, with the reforming as the main reaction, CO2 gasification and methane pyrolysis as the side reaction. Catalytic activity varies from one carbonaceous material to another, but their reaction trend is the same on the whole. Those high specific surface area carbonaceous materials show higher catalytic activity. The increase in reaction temperature and residence time of the reforming can improve the conversion of reactant gas. Adjusting the partial pressure of methane can control carbon–hydrogen ratio of the synthesis gas. XPS and XRD characterizations demonstrate that the structural ordering of carbonaceous materials becomes a little messier after the reforming reaction, and the number and content of oxygen functional groups decrease. That means these oxygen functional groups on the surface of carbonaceous materials are involved in the reforming and these groups along with pore structure on the surface are the major factors influencing the catalytic properties. Different oxygen species make the nature of electrical energy on the surface different; the catalytic activity depends on the polarity of oxygen from different species. Those whose polarity is strong have strong activity. The dipole force can be associated with methane in the form of hydrogen bond, so that the material can display strong activity. Those whose polarity is weak have weak activity, the catalytic activity is weak too. The results of chemical titration and XPS characterization show that the oxygen in the anhydride and lactone structures on the surface of carbonaceous materials are active oxygen, and which is the main active component, it can reduce the activation energy of methane dehydrogenation.