نتایج جستجو برای: silica supported catalysts

تعداد نتایج: 257434  

The CO preferential oxidation (PrOx) is one of the critical steps in hydrogen production and purification for Polymer Electrolyte Membrane Fuel Cell (PEMFC). This reaction was investigated in the presence of excess hydrogen over Cu/CeO2, Pt/CeO2 and Cu-Pt/CeO2 catalysts. The ceria supports was prepared via precipitation method and Cu-Pt/CeO2 catalyst was synthesized by sequential impregnation o...

Journal: :Journal of the American Chemical Society 2012
Lefu Yang Shiyao Shan Rameshwori Loukrakpam Valeri Petkov Yang Ren Bridgid N Wanjala Mark H Engelhard Jin Luo Jun Yin Yongsheng Chen Chuan-Jian Zhong

The understanding of the atomic-scale structural and chemical ordering in supported nanosized alloy particles is fundamental for achieving active catalysts by design. This report shows how such knowledge can be obtained by a combination of techniques including X-ray photoelectron spectroscopy and synchrotron radiation based X-ray fine structure absorption spectroscopy and high-energy X-ray diff...

2017
Tamás I. Korányi Xiaoming Huang Alessandro E. Coumans Emiel J. M. Hensen

The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu-Mg-Al oxide (CuMgAlO x ) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e. Ni/SiO2, Ni2P/SiO2, and Ni/ASA (ASA = amorphous silica alumina), with the aim of combining lignin de...

Journal: :Chemical science 2017
Janet C Mohandas Edy Abou-Hamad Emmanuel Callens Manoja K Samantaray David Gajan Andrei Gurinov Tao Ma Samy Ould-Chikh Adam S Hoffman Bruce C Gates Jean-Marie Basset

Air-stable catalysts consisting of tantalum nitride nanoparticles represented as a mixture of Ta x N y and TaO x N y with diameters in the range of 0.5 to 3 nm supported on highly dehydroxylated silica were synthesized from TaMe5 (Me = methyl) and dimeric Ta2(OMe)10 with guidance by the principles of surface organometallic chemistry (SOMC). Characterization of the supported precursors and the s...

Journal: :Chemistry 2007
Lei Zhang Hendrikus C L Abbenhuis Gijsbert Gerritsen Nollaig Ní Bhriain Pieter C M M Magusin Brahim Mezari Wei Han Rutger A van Santen Qihua Yang Can Li

A novel interfacial hybrid epoxidation catalyst was designed with a new immobilization method for homogeneous catalysts by coating an inorganic support with an organic polymer film containing active sites. The titanium silsesquioxane (TiPOSS) complex, which contains a single-site titanium active center, was immobilized successfully by in-situ copolymerization on a mesoporous SBA-15-supported po...

2017
Wenpei Gao Massimo Colombo Sheng Dai Shuyi Zhang George Graham Xiaoqing Pan Frederick Reines Hall

The use of closed, electron transparent gas cells to perform in situ scanning/ transmission electron microscopy (S/TEM) now enables visualization of the atomic structure of catalysts at variable temperature in a gas environment, which may be close to real operational conditions [1]. When coupled with energy dispersive spectroscopy (EDS) detector, in situ composition analysis can be achieved at ...

Journal: :Journal of the American Chemical Society 2014
Yuying Meng Damien Voiry Anandarup Goswami Xiaoxin Zou Xiaoxi Huang Manish Chhowalla Zhongwu Liu Tewodros Asefa

Replacing rare and expensive metal catalysts with inexpensive and earth-abundant ones is currently among the major goals of sustainable chemistry. Herein we report the synthesis of N-, O-, and S-tridoped, polypyrrole-derived nanoporous carbons (NOSCs) that can serve as metal-free, selective electrocatalysts and catalysts for oxygen reduction reaction (ORR) and alcohol oxidation reaction (AOR), ...

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