نتایج جستجو برای: catalyst activity

تعداد نتایج: 1169846  

A magnetically recoverable catalyst consisting of Mn (III) salophen complex was prepared. The synthesized catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared (FT-IR). The immobilized catalyst was shown to be an ef...

Journal: :Angewandte Chemie 2015
Qing Li Xiaodong Wen Gang Wu Hoon T Chung Rui Gao Piotr Zelenay

Dimethyl ether (DME) has been considered as a promising alternative fuel for direct-feed fuel cells but lack of an efficient DME oxidation electrocatalyst has remained the challenge for the commercialization of the direct DME fuel cell. The commonly studied binary PtRu catalyst shows much lower activity in DME than methanol oxidation. In this work, guided by density functional theory (DFT) calc...

2011
Karim H. Hassan M. Rahman

Hydrogen sulfide removal catalyst was prepared chemically by precipitation of zinc bicarbonate at a controlled pH. The physical and chemical catalyst characterization properties were investigated. The catalyst was tested for its activity in adsorption of H2S using a plant that generates the H2S from naphtha hydrodesulphurization and a unit for the adsorption of H2S. The results comparison betwe...

2017
Wei Wang Zongyuan Wang Jiajun Wang Chuan‐Jian Zhong Chang‐Jun Liu

Carbon-supported platinum (Pt) and palladium (Pd) alloy catalyst has become a promising alternative electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. In this work, the synthesis of highly active and stable carbon-supported Pt-Pd alloy catalysts is reported with a room-temperature electron reduction method. The alloy nanoparticles thus prepared show a pa...

2014
B. K. Miller T. M. Barker P. A. Crozier

In situ studies of catalysts in the environmental transmission electron microscope (ETEM) are of great value to elucidate the structure of a catalyst under reaction conditions. This is important, since the structure of many catalysts change at elevated temperature in the presence of reactive gases [1-2]. One way to directly relate structure to activity is to measure the activity of the catalyst...

2015
Qi Lu Gregory S Hutchings Weiting Yu Yang Zhou Robert V Forest Runzhe Tao Jonathan Rosen Bryan T Yonemoto Zeyuan Cao Haimei Zheng John Q Xiao Feng Jiao Jingguang G Chen

A robust and efficient non-precious metal catalyst for hydrogen evolution reaction is one of the key components for carbon dioxide-free hydrogen production. Here we report that a hierarchical nanoporous copper-titanium bimetallic electrocatalyst is able to produce hydrogen from water under a mild overpotential at more than twice the rate of state-of-the-art carbon-supported platinum catalyst. A...

2016
Zhongbin Zhuang Stephen A. Giles Jie Zheng Glen R. Jenness Stavros Caratzoulas Dionisios G. Vlachos Yushan Yan

The development of a low-cost, high-performance platinum-group-metal-free hydroxide exchange membrane fuel cell is hindered by the lack of a hydrogen oxidation reaction catalyst at the anode. Here we report that a composite catalyst, nickel nanoparticles supported on nitrogen-doped carbon nanotubes, has hydrogen oxidation activity similar to platinum-group metals in alkaline electrolyte. Althou...

Journal: :Plant physiology 1981
J A Guikema C F Yocum

Photosystem II-dependent cyclic photophosphorylation activity produced by addition of p-phenylenediamines to KCN-Hg-NH(2)OH-inhibited chloroplasts is the product of two separate reactions when a proton/electron donor is the catalyst. The activity observed with an electron donor as catalyst consists of a single reaction. One of the cyclic reactions, evoked by low (</=40 micromolar) concentration...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد 1387

چکیده ندارد.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده علوم 1386

چکیده ندارد.

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