共查询到18条相似文献,搜索用时 62 毫秒
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甲烷光催化氧化制甲醇研究进展 总被引:2,自引:0,他引:2
随着经济的发展,人们对能源的需求量日益增加.目前,世界上石油资源储量有限,而天然气是非常丰富的石油化工燃料资源,储量很大.现已探明的世界天然气储量为142.1万亿立方米,其能量相当于9143亿桶原油,远景储量为250~350万亿立方米.天然气资源与液体石油资源相比,其储量 相似文献
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NOx气相光催化氧化降解研究 总被引:24,自引:0,他引:24
利用TiO2光催化氧化技术对NOx进行了净化研究,在一定反应条件下,NOx光催化氧化降解率很高,P-25的降解达97%。考察了氧气,水含量等对NOx光催化氧化的影响,同时对NOx的吸附、光催化氧化动力学行为及机理进行了研究。利用FTIR分析确定反应产物,催化剂失活是由于反应产物硝酸吸附在催化剂表面所致。 相似文献
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甲醇阳极电氧化催化剂的研究 总被引:4,自引:1,他引:4
采用化学还原沉积法制备了Pt-WO3/C,Pt-Ru/C和Pt-WO3/C系列催化剂,通过循环伏安与电流-电位极化研究了甲醇在不同催化剂/Nafion奄极上的电催化氧化。结果表明,三种催化剂的催化活性顺序为:Pt-Ru-WO3/C〉Pt-Ru/C〉Pt-WO3/C。同时研究了甲醇浓度和催化剂的配比对阳极性能的影响。 相似文献
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对苯二胺衍生物的光催化氧化 总被引:1,自引:0,他引:1
以TiO2作为催化剂,利用波长>330nm的光辐照研究了N-取代的对苯-二胺衍生物的光催化氧化。研究表明,氧分子与光生电子 反应生成羟基自由基,羟基自由基氧化PPDs,生成醌二亚胺,后者在羟基的进攻下脱氨生成苯醌,苯醌继续光解无机化。PPDs光催化氧化近似遵循一级反应动力学,醇类和硫酸根离子可抑制PPDs的光催化氧化。催化剂表面荷影响电子转移速率,从而控制光催化氧化的反应速率。 相似文献
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甲醇气相氧化羰基化合成碳酸二甲酯的研究 总被引:11,自引:2,他引:11
制备了甲醇气相氧化羰基化催化合成碳酸二甲酯催化剂,在常压固定床反应装置上评价了其反应性能,考察了且剂和载体的影响。结果表明:负载在活性炭载体上的单一金属氯化物催化剂的活性相当低,而双金属氯化物催化剂PdCl2-CuCl2/AC可明显提高碳酸二甲酯的产率。不同的活性炭载体显著地反应活性。碱性助剂K、Mg能大幅度增加碳酸二甲酯的时空收率和对CO的选择性,但必需以乙酸的形式加入,PdCl-CuCl2-C 相似文献
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TiO2气相光催化氧化降解三氯乙烯的产物分布及失活机理研究 总被引:6,自引:0,他引:6
用GC/MS、TPD和XPS方法,研究了三氯乙烯的气相光催化降解反应,检测到新的中间体乙二酰氯(CICOCOCI)。对产物分布的分析表明,水蒸汽的存在能显著抑制含氯副产物的生成,改变反应产物的分布。使用过的催化剂的XPS谱图显示,催化剂表面存在含氯副产物,反应副产物在催化剂表面的积累是导致催化剂失活的主要原因。 相似文献
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Gita Yuniar Wibawa Hendra Saputera Dwiwahju Sasongko Rino R. Mukti Jenny Rizkiana Hary Devianto 《Molecules (Basel, Switzerland)》2022,27(17)
Methane is one of the promising alternatives to non-renewable petroleum resources since it can be transformed into added-value hydrocarbon feedstocks through suitable reactions. The conversion of methane to methanol with a higher chemical value has recently attracted much attention. The selective oxidation of methane to methanol is often considered a “holy grail” reaction in catalysis. However, methanol production through the thermal catalytic process is thermodynamically and economically unfavorable due to its high energy consumption, low catalyst stability, and complex reactor maintenance. Photocatalytic technology offers great potential to carry out unfavorable reactions under mild conditions. Many in-depth studies have been carried out on the photocatalytic conversion of methane to methanol. This review will comprehensively provide recent progress in the photocatalytic oxidation of methane to methanol based on materials and engineering perspectives. Several aspects are considered, such as the type of semiconductor-based photocatalyst (tungsten, titania, zinc, etc.), structure modification of photocatalyst (doping, heterojunction, surface modification, crystal facet re-arrangement, and electron scavenger), factors affecting the reaction process (physiochemical characteristic of photocatalyst, operational condition, and reactor configuration), and briefly proposed reaction mechanism. Analysis of existing challenges and recommendations for the future development of photocatalytic technology for methane to methanol conversion is also highlighted. 相似文献
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纳米Pt/TiO2催化剂上气相CH3OH光催化分解制氢反应的研究 总被引:7,自引:0,他引:7
利用不同还原方法制备了不同纳米粒度的Pt/tiO2光催化剂,并且用脉冲氢氧滴定法测定了TiO2表面Pt的分散度.在气相连续流动装置中利用纳米Pt/tiO2作为光催化剂,对气相甲醇的脱氢反应进行了研究.研究了添加Pt和不添加Pt的纳米TiO2,Pt负载量、铂的不同还原方法、不同TiO2纳米粒度对气相甲醇光催化分解反应的影响,并对反应气的空速、光照时间、添加水蒸汽、改变甲醇浓度等与光催化分解甲醇制氢的关系进行了研究,在最佳反应条件下,产氢速率达到5.808 mmol/(g·h).研究了反应的动力学,得到该反应为一级反应,求得了该反应的活化能为8.53 kJ/mol,并讨论了反应机理. 相似文献
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掺铁TiO2气相光催化降解正己烷的研究 总被引:6,自引:0,他引:6
利用钛酸丁酯水解浸渍、共沉淀、水热等方法制备了掺铁TiO2纳米复合粉体材料并通过XRD、BET、TEM等手段作了表征,研究了掺铁TiO2对气相光催化降解正己烷反应的活性并和商品TiO2 Degussa P-25作了比较,考察了制法、掺铁量、焙烧温度等的影响。结果表明,和大多数液相反应不同,铁的掺入抑制了TiO2对正己烷的气相光催化降解。水热处理能较大程度地改善掺铁和未掺铁TiO2的光催化性能。P-25对正己烷的气相光催化活性则明显小于未掺铁TiO2样品,也小于某些掺铁样品。 相似文献
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Zongwei Chen Prof. Dr. Qun Zhang Prof. Dr. Yi Luo 《Angewandte Chemie (International ed. in English)》2018,57(19):5320-5324
An experimental scrutiny of the photoexcited hole dynamics in a prototypical system is presented in which hole‐scavenging methanol molecules are chemisorbed on a graphitic carbon nitride (g‐C3N4) substrate. A set of comparison and control experiments by means of femtosecond time‐resolved transient absorption (fs‐TA) spectroscopy were conducted. The elusive reverse hole transfer (RHT) process was identified, which occurs on a timescale of a few hundred picoseconds. The critical role of interfacially chemisorbed methoxy (instead of methanol) as the dominant species responsible for hole scavenging was confirmed by a control experiment using protonated g‐C3N4 as the substrate. A hot‐hole transfer effect was revealed by implementing different interband photoexcitation scenarios. The RHT rate is the key factor governing the hole‐scavenging ability of different hole scavengers. 相似文献
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Mesoporous RuO2–TiO2 nanocomposites at different RuO2 concentrations (0–10 wt %) are prepared through a simple one‐step sol–gel reaction of tetrabutyl orthotitanate with ruthenium(III) acetylacetonate in the presence of an F127 triblock copolymer as structure‐directing agent. The thus‐formed RuO2–TiO2 network gels are calcined at 450 °C for 4 h leading to mesoporous RuO2–TiO2 nanocomposites. The photocatalytic CH3OH oxidation to HCHO is chosen as the test reaction to examine the photocatalytic activity of the mesoporous RuO2–TiO2 nanocomposites under UV and visible light. The photooxidation of CH3OH is substantially affected by the loading amount and the degree of dispersion of RuO2 particles onto the TiO2, which indicates the exclusive effect of the RuO2 nanoparticles on this photocatalytic reaction under visible light. The measured photonic efficiency ξ=0.53 % of 0.5 wt % RuO2–TiO2 nanocomposite for CH3OH oxidation is maximal and the further increase of RuO2 loading up to 10 wt % gradually decreases this value. The cause of the visible‐light photocatalytic behavior is the incorporation of small amounts of Ru4+ into the anatase lattice. On the other hand, under UV light, undoped TiO2 shows a very good photonic efficiency, which is more than three times that for commercial photocatalyst, P‐25 (Evonik–Degussa); however, addition of RuO2 suppresses the photonic efficiency of TiO2. The proposed reaction mechanism based on the observed behavior of RuO2–TiO2 photocatalysts under UV and visible light is explored. 相似文献
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IntroductionA broad range of orgainc compounds[1 ,2 ]can be oxidized by means of semiconductor pho-tocatalysis with a primary focus on Ti O2 as a durable photocatalyst in recent years.WhenTi O2 is illuminated with the light of energy greater than the semiconductor band gap,elec-tron- hole pairs(e-- h ) are formed in the conduction and thevalence bandsof thesemiconduc-tor,respectively.These charge carriers,which migrate to the semiconductor surface,are ca-pable of activating oxygen species,et… 相似文献