نتایج جستجو برای: precious metal

تعداد نتایج: 201716  

2015
Nastaran Ranjbar Sahraie Ulrike I Kramm Julian Steinberg Yuanjian Zhang Arne Thomas Tobias Reier Jens-Peter Paraknowitsch Peter Strasser

Carbon materials doped with transition metal and nitrogen are highly active, non-precious metal catalysts for the electrochemical conversion of molecular oxygen in fuel cells, metal air batteries, and electrolytic processes. However, accurate measurement of their intrinsic turn-over frequency and active-site density based on metal centres in bulk and surface has remained difficult to date, whic...

2016
Lin Zhou Xiaoxiao Li Ze Yao Zhuwen Chen Mei Hong Rongshu Zhu Yongye Liang Jing Zhao

Catalytic oxidation of carbon monoxide (CO) is of great importance in many different fields of industry. Until now it still remains challenging to use non-noble metal based catalysts to oxidize CO at low temperature. Herein, we report a new class of nanoporous, uniform, and transition metal-doped cerium (IV) oxide (ceria, CeO2) microsphere for CO oxidation catalysis. The porous and uniform micr...

Journal: :Nature communications 2015
Julian G West David Huang Erik J Sorensen

The dehydrogenation of unactivated alkanes is an important transformation both in industrial and biological systems. Recent efforts towards this reaction have revolved around high temperature, organometallic C-H activation by noble metal catalysts that produce alkenes and hydrogen gas as the sole products. Conversely, natural desaturase systems proceed through stepwise hydrogen atom transfer at...

Journal: :Nanoscale 2017
Xiaoxiao Huang Ziyu Yang Bing Dong Yazhou Wang Tianyu Tang Yanglong Hou

Developing efficient and economical noble-metal free catalysts for oxygen reduction reaction (ORR) is one of the essential factors for the industrialization of fuel cells. Recent studies on transition metal ORR catalysts have become the priority to practical low-temperature fuel cells. Herein, we proposed a novel in situ design, Fe2N nanoparticles (NPs) in an N doped porous carbon matrix (Fe2N@...

2008
M. H. Barker

This reaction is connected to high overpotentials, which are in Zn electrowinning about 800 mV, or 20–25% of the total cell voltage, and with that an equal amount of the total electrical energy1. Many attempts have been made to reduce the overpotential by introducing better catalysts. The main anode systems are nowadays all lead based1, which offer the best cost:value ratio for most of the indu...

2014
Nicolas P. E. Barry Anaïs Pitto-Barry Ana M. Sanchez Andrew P. Dove Richard J. Procter Joan J. Soldevila-Barreda Nigel Kirby Ian Hands-Portman Corinne J. Smith Rachel K. O’Reilly Richard Beanland Peter J. Sadler

Metal nanocrystals offer new concepts for the design of nanodevices with a range of potential applications. Currently the formation of metal nanocrystals cannot be controlled at the level of individual atoms. Here we describe a new general method for the fabrication of multi-heteroatom-doped graphitic matrices decorated with very small, ångström-sized, three-dimensional (3D)-metal crystals of d...

2016
Dustin R. Cummins Ulises Martinez Andriy Sherehiy Rajesh Kappera Alejandro Martinez-Garcia Roland K. Schulze Jacek Jasinski Jing Zhang Ram K. Gupta Jun Lou Manish Chhowalla Gamini Sumanasekera Aditya D. Mohite Mahendra K. Sunkara Gautam Gupta

Hydrogen evolution reaction is catalysed efficiently with precious metals, such as platinum; however, transition metal dichalcogenides have recently emerged as a promising class of materials for electrocatalysis, but these materials still have low activity and durability when compared with precious metals. Here we report a simple one-step scalable approach, where MoOx/MoS2 core-shell nanowires ...

2008
Gang Wu Zhongwei Chen Kateryna Artyushkova Fernando H. Garzon Piotr Zelenay

This paper focuses on a new polyaniline-derived non-precious cathode catalyst with high oxygen-reduction activity, verified in electrochemical and fuel cell testing. The rotating disk (RDE) onset and half-wave potential (E1⁄2) of oxygen reduction were measured at 0.90 V and 0.77 V, respectively. Rotating ring-disk electrode (RRDE) study revealed very good selectivity in the fourelectron reducti...

Journal: :SusMat 2023

Oxygen reduction reaction (ORR) is an electrochemical in which dissolved oxygen electrolyte reduced to OH?/H2O when receiving electrons. This plays a crucial role shaping the efficiency of both metal–air batteries and fuel cells, precious metals are dominant catalysts carrying out ORR their cathodes. However, how manipulate electronic structure as active sites further promote performance maximi...

Journal: :Chemical communications 2014
Jie Zhang Jianming Geng Guiming Zheng Jingcao Dai Zhiyong Fu

A unique hydrothermal selective hydrogenation process is carried out effectively in a simple and friendly way without adding any precious metal catalysts and hydrogen gas from outside. The self-assembly of the hydrogenated product 3-(4-(pyridin-4-yl)piperidin-1-yl) benzoate (PYPDB) with the zinc ion produces a highly stable photoactive complex Zn(PYPDB)2 displaying interesting long range electr...

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