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111.
IntroductionThepreparativeapproachofaneffectivebilTldslliccatalystisalwaysasubjectofboortantsignificanceinheterogeneouscatalysis.InourrecentstUdies,wefoundthatthebAnetallitcarbonylclustercoCo3(CO)12favorablygivesthebAnetalliccoCo3clusterontheSiOZsubdueaft… 相似文献
112.
Lin Jia Hui Yang Jun Deng Junmei Chen Yuan Zhou Pan Ding Leigang Li Na Han Yanguang Li 《中国化学》2019,37(5):497-500
Electrocatalytic carbon dioxide reduction holds great promise for reducing the atmospheric CO2 level and alleviating the energy crisis. High‐performance electrocatalysts are often required in order to lower the high overpotential and expedite the sluggish reaction kinetics of CO2 electroreduction. Copper is a promising candidate metal. However, it usually suffers from the issues of poor stability and low product selectivity. In this work, bimetallic Cu‐Bi is obtained by reducing the microspherical copper bismuthate (CuBi2O4) for selectively catalyzing the CO2 reduction to formate (HCOO–). The bimetallic Cu‐Bi electrocatalyst exhibits high activity and selectivity with the Faradic efficiency over 90% in a wide potential window. A maximum Faradaic efficiency of ~95% is obtained at –0.93 V versus reversible hydrogen electrode. Furthermore, the catalyst shows high stability over 6 h with Faradaic efficiency of ~95%. This study provides an important clue in designing new functional materials for CO2 electroreduction with high activity and selectivity. 相似文献
113.
A review of the chemical and physical properties of MnRe(CO)10 and its derivatives has been undertaken. This heterobimetallic complex is one of the simplest complexes known which contains a bond between two different metals and does not contain bridging groups. The review has revealed that high yield synthetic strategies are known for this complex and the synthetic strategies have bearing for the synthesis of other bimetallic complexes. Kinetic data suggest that information available on monometallic fragments can provide information on the reactivity trends expected for the dimer. However, the second metal is not a neutral spectator and provides a site forsecondary reactions eg for CO substitution. Data on the physical properties of the dimer are sparse and definitive statements ond
Mn-Re·v
Mn-Re, HMn-Re etc. cannot be made. This has significant implications for studies on related simple and complex dimer and cluster complexes. 相似文献
114.
Zhigang Liu Renxian Zhou Xiaoming Zheng 《天然气化学杂志》2007,16(2):167-172
The CuO-CeO2 catalyst prepared by chelating method has a superior catalytic performance for the preferential oxidation of CO in rich hydrogen, compared with the CuO-CeO2 catalyst prepared by coprecipitation method. The CO conversions over these catalysts, at 120℃and 120000 ml/(g-h) in the absence of CO2 and H2O, are 99.6% and 88.6%, respectively, and the selectivity of O2 over these catalysts is very close (i.e. 51.3% and 55.8%, respectively). The influence of certain factors such as hydrogen concentration, carbon monoxide concentration, H2O, O2/CO ratios, and space velocity on the catalytic performance of CuO-CeO2 catalyst prepared by chelating method is also studied. The results show that the addition of hydrogen and H2O has a negative effect on the catalytic performance of CuO-CeO2 catalyst, however, the variation of space velocity and the O2/CO ratio causes a comparatively slight influence. 相似文献
115.
CuO/CeO2催化剂的催化氧化性能及其表征 总被引:9,自引:4,他引:9
用CO流动反应法 ,程序升温还原 (TPR) ,光电子能谱 (XPS)和X射线衍射Rietveld分析等技术研究了CuO ,CeO2 及CuO/CeO2 各组分催化剂。结果表明 :单组分的CuO和CeO2 对CO的氧化活性较低 ,但CuO与CeO2 形成复合氧化物后 ,其CO氧化活性明显提高 ,这可能与铜物种在CeO2 表面的价态 (Cu2 + 和Cu+ ) ,分散状态和还原性能有关。CuO在CeO2 上的负载量对铜物种在CeO2 表面形成的价态 (Cu2 + 和Cu+ )至关重要 ,CuO的负载量为 1 0 %时 ,XPS检测不到Cu2p3/2 (eV)结合能 ;当CuO的负载量为 5 0 %时 ,CuO主要以Cu2 + 和Cu+ 形式存在 ,而负载量大于 5 0 %时 ,CuO则以Cu2 + 形式存在。由于形成了CuO/CeO2 复合氧化物 ,使离子半径小于Ce4 + 的CuO进入了CeO2 晶格 ;当CuO的负载量达到 5 0 %时 ,CuO的晶粒尺寸值为最小 ( 6 1nm) ,而晶格畸变值为最大 ( 2 86× 10 - 3) ,此时 ,催化剂具有较高的表面能和最佳的CO氧化活性 相似文献
116.
Peter Brodelius Kjell Nilsson Klaus Mosbach 《Applied biochemistry and biotechnology》1981,6(4):293-307
Whole cells ofTrigonopsis variabilis were immobilized by entrapment in Ca2+-alginate and used for the production of α-keto acids from the corresponding D-amino acids. The D-amino acid oxidase within
the immobilized cells has a broad substrate specificity. Hydrogen peroxide formed in the enzymatic reaction was efficiently
hydrolyzed by manganese oxide co-immobilized with the cells. The amino acid oxidase activity was assayed with a new method
based on reversed-phase HPLC. Oxygen requirements, bead size, concentration of cells in the beads, flow rate, and other factors
were investigated in a “ trickle-bed ” reactor. 相似文献
117.
The chemical reactions and kinetics of the catalytic coupling reaction of carbon monoxide to diethyl oxalate were studied in the presence of hydrogen over a supported palladium catalyst in the gaseous phase at the typical coupling reaction conditions. The experiments were performed in a continuous flow fixed-bed reactor. The results indicated that hydrogen only reacts with ethyl nitrite to form ethanol, and kinetic studies revealed that the rate-determining step is the surface reaction of adsorbed hydrogen and the ethoxy radical (EtO-). A kinetic model is proposed and a comparison of the observed and calculated conversions showed that the rate expressions are of rather high confidence. 相似文献
118.
119.
Ogata Atsushi Mizuno Koichi Kushiyama Satoshi Yamamoto Toshiaki 《Plasma Chemistry and Plasma Processing》1998,18(3):363-373
The behavior of lattice oxygen species of the ferroelectric material during methane oxidation was investigated using a nonthermal plasma reactor packed with BaTiO
3
pellets. Lattice oxygen species in BaTiO
3
play an important role in the formation of N
2
O and the oxidation of CH
4
. The oxidation products such as CO and CO
2
were formed from independent reaction pathways. Lattice oxygen species were able to preferentially oxidize the carbon species deposited on the pellet surface into CO. Also, N
2
O and NO
x
were independently formed in the N
2–O
2
reaction, suggesting that different oxygen species give N
2
O and NO
x. N
2
O was produced by the oxidation of molecular nitrogen with lattice oxygen species. 相似文献
120.
Kinetics of CO oxidation on the surface of heterophase catalysts. Modeling by the Monte Carlo method
The Monte Carlo method has been used to simulate CO oxidation on a lattice consisting of various alternating patches: M1, where s(CO)>s(O2) and M2, where s(CO)2). The reaction is shown to proceed over all the surface at low temperature as COads spillover from M1 to M2 and backwards. 相似文献