摘要:

Catalysis research underpins the science of modem chemical processing and fuel technologies. Catalysis is one of the most important technologies commercially in national economies. Solid-state heterogeneous catalyst materials such as metal oxides or metal particles on ceramic oxide substrates are most common. They are typically used with commodity gases and liquid reactants. Selective oxidation catalysis of hydrocarbon feedstocks is the dominant process converting them to key industrial chemicals, polymers, and energy sources, and is the basis of this review.

ISSN:0161-4940    

DOI:10.1080/01614949208021918

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The study of systems with dimensions of the order of a few to a hundred nanometers has attracted great attention. The main reason is the peculiar physical and chemical behavior of these systems; they are specially important in catalysts since metal nano particles are the most common constituents of the supported catalysts. The understanding of the structure of nano particles is a crucial step for the understanding of the catalytic activity. In the present work we report a number of transmission electron microscopy techniques that can be used in order to characterize the shape and structure of nano particles. In the last decade electron microscopy has had a dramatic development and at the present time we have a number of techniques from medium-resolution such as selected zone dark-field (SZDF) and weak beam dark-field (WBDF) as well as direct atom imaging by high resolution. In the present work we discuss the theoretical principles of these techniques and their main applications to the field of nano particle characterization.

ISSN:0161-4940    

DOI:10.1080/01614949208021919

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Advances in instrumentation have made it possible in recent years to study the microstructure of inorganic materials at atomic resolution using the technique of high-resolution electron microscopy (HREM). Details of instrumentation have been described elsewhere [l], and applications and trends for HREM have recently been reviewed [2]. Although HREM is primarily a technique for studying bulk defects, it is increasingly also being applied in the profile-imaging mode to derive information about surfaces [3]. The high spatial resolution of the electron microscope makes it a valuable tool for the characterization of heterogeneous catalysts. This is evidenced by the growing number of studies wherein electron micrographs are being used to describe the morphology of a particular catalyst. Profile imaging is proving particularly useful in this regard for following changes in surface structure as a function of treatment conditions [4].

ISSN:0161-4940    

DOI:10.1080/01614949208021920

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0161-4940    

DOI:10.1080/01614949208021917

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor