نتایج جستجو برای: zn fealumina catalyst

تعداد نتایج: 82294  

Journal: :Angewandte Chemie 2014
Matthias B Fichtl Julia Schumann Igor Kasatkin Nikolas Jacobsen Malte Behrens Robert Schlögl Martin Muhler Olaf Hinrichsen

Different surface sites of solid catalysts are usually quantified by dedicated chemisorption techniques from the adsorption capacity of probe molecules, assuming they specifically react with unique sites. In case of methanol synthesis catalysts, the Cu surface area is one of the crucial parameters in catalyst design and was for over 25 years commonly determined using diluted N2O. To disentangle...

2006
Aydin Akgerman

INTRODUCTION The conversion of synthesis gas to methanol is practiced commercially in gas phase fixed bed reactors over a Cu/Zn/Al,O1 catalyst. However, because of the highly exothermic nature of the synthesis reactions, heat dissipation has been a bottleneck in the reactor design and process configuration. Moreover, coalderived synthesis gas, having a low H,/CO ratio, is not suitable for use i...

2017
Jijie Wang Guanna Li Zelong Li Chizhou Tang Zhaochi Feng Hongyu An Hailong Liu Taifeng Liu Can Li

Although methanol synthesis via CO hydrogenation has been industrialized, CO2 hydrogenation to methanol still confronts great obstacles of low methanol selectivity and poor stability, particularly for supported metal catalysts under industrial conditions. We report a binary metal oxide, ZnO-ZrO2 solid solution catalyst, which can achieve methanol selectivity of up to 86 to 91% with CO2 single-p...

2009
Shuli Yan Steven O. Salley K. Y. Simon Ng

A single-step method was developed for biodiesel production from unrefined or waste oils using a series of heterogeneous zinc and lanthanum mixed oxides. Effects of metal oxide molar ratio, free fatty acids (FFA) and water content in feedstock, molar ratio of methanol and oil, and reaction temperature on the yield of biodiesel were investigated. A strong interaction between Zn and La species wa...

Journal: :Organic & biomolecular chemistry 2012
Tuomas Lönnberg Mikko Luomala

The general acid/base catalyzed cleavage of a number of alkyl esters of uridine-3'- (and -5'-)phosphate has been studied by utilizing a cleaving agent, in which the catalytic moiety (a substituted 1,3,5-triazine) is tethered to an anchoring Zn(II):cyclen moiety. Around pH 7, formation of a strong ternary complex between uracil, Zn(II) and cyclen brings the general acid/base catalyst close to th...

2010
Ying Xiao Emily C. Allen Scott K. Silverman

Metal ions can significantly expand the scope of macromolecular catalysis. For catalysts composed of nucleic acids (DNA or RNA), metal ions are typically required for both structural and catalytic roles. Divalent metal ions such as Mg, Mn, and Zn are often, but not always, obligatory cofactors for ribozymes and deoxyribozymes. We recently described the 10MD5 deoxyribozyme as an example of a hig...

2017
Rui M. B. Carrilho Lucas D. Dias Raquel Rivas Mariette M. Pereira Carmen Claver Anna M. Masdeu-Bultó

Metal complexes of meso-arylporphyrins (Cr(III), Fe(III), and Zn(II)) were evaluated in the coupling reaction of cyclohexene oxide (CHO) with CO2 in compressed medium, where the Cr complexes were demonstrated to be the most active systems, leading predominantly to copolymerisation products. It is noteworthy that no addition of solvent was required. To improve the catalytic activity, and to simu...

2016
Hugo Schiff

Metal chelates of Schiff base prepared by combining salicylaldehyde and amino acids could be effectively used in understanding the mechanism of transamination reaction. They can act as biomimetic species. The current article focused on the syntheses, characterization, complexation behaviour and antimicrobial studies of some novel Schiff bases formed from salicylaldehyde with 3-amino benzoic aci...

Journal: :Journal of materials chemistry 2011
Jian Shi Hao Hong Yong Ding Yunan Yang Weibo Cai Xudong Wang

In-depth understanding of the kinetics of the vapor deposition process is substantial for advancing this capable bottom-up nanostructure synthesis approach into a versatile large-scale nanomanufacturing technology. In this paper, we report a systematic study of the vapor deposition kinetics of ZnO nanomaterials under controlled atmosphere and properly refined deposition conditions. The experime...

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