The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...

http://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.5b00482

Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

To improve fuel efficiency, advanced combustion engines are being designed to minimize the amount of heat wasted in the exhaust. Hence, future generations of catalysts must perform at temperatures that are 100°C lower than current exhaust-treatment catalysts. Achieving low-temperature activity, while surviving the harsh conditions encountered at high engine loads, remains a formidable challenge. In this study, we demonstrate how atomically dispersed ionic platinum (Pt2+) on ceria (CeO2), which is already thermally stable, can be activated via steam treatment (at 750°C) to simultaneously achieve the goals of low-temperature carbon monoxide (CO) oxidation activity while providing outstanding hydrothermal stability. A new type of active site is created on CeO2 in the vicinity of Pt2+, which provides the improved reactivity. These active sites are stable up to 800°C in oxidizing environments.

http://science.sciencemag.org/content/sci/358/6369/1419.full.pdf

Activation of surface lattice oxygen in single-atom Pt/CeO2 for low-temperature CO oxidation

4.1. Noble Metals 4058 4.1.1. Platinum 4059 4.1.2. Palladium 4060 4.1.3. Bimetallic Systems 4060 4.2. Storage Components 4061 4.2.1. Earth Alkaline Metals 4061 4.2.2. Alkali Metals 4065 4.3. Supports 4065 4.3.1. Single Oxides 4065 4.3.2. Mixed Oxides 4067 4.4. Promoters 4069 4.5. Preparation Methods 4071 4.6. Influence of Remote Control 4073 5. Influence of Exhaust Gas Composition 4074 5.1. Reducing Gas 4074 5.2. Water 4077 5.3. Carbon Dioxide 4077 5.4. Impact of Soot 4079 6. Theoretical and Surface Science Studies 4079 6.1. Theoretical Studies 4079 6.2. Studies on Well-Defined Model Catalysts 4082 7. Reactor Configuration 4082 8. Conclusions and Outlook 4086 9. Acknowledgments 4087 10. References 4087

NOx Storage−Reduction Catalysis: From Mechanism and Materials Properties to Storage−Reduction Performance

In the past decade or so, small-pore zeolites have received greater attention than large- and medium-pore molecular sieves that have historically dominated the literature. This is primarily due to the commercialization of two major catalytic processes, NOx exhaust removal and methanol conversion to light olefins, that take advantage of the properties of these materials with smaller apertures. Small-pore zeolites possess pores that are constructed of eight tetrahedral atoms (Si4+ and Al3+), each time linked by a shared oxygen These eight-member ring pores (8MR) provide small molecules access to the intracrystalline void space, e.g., to NOx during car exhaust cleaning (NOx removal) or to methanol en route to its conversion into light olefins, while restricting larger molecule entrance and departure that is critical to overall catalyst performance. In total, there are forty-four structurally different small-pore zeolites. Forty-one of these zeolites can be synthesized, and the first synthetic zeolite (KFI, 1...

Small-Pore Zeolites: Synthesis and Catalysis

The paper summarizes the key developments in diesel emission control, generally for 2005. Regulatory targets for the next 10 years and projected advancements in engine technology are used to estimate future emission control needs. Recent NOx control developments on selective catalytic reduction (SCR), lean NOx traps (LNT) and lean NOx catalysts (LNC) are then summarized. Likewise, the paper covers important recent developments on diesel particulate filters (DPFs), summarizing regeneration strategies, new filter and catalyst materials, ash management, and PM measurement. Recent developments in diesel oxidation catalysts are also briefly summarized. Finally, the paper discusses examples of how it is all pulled together to meet the tightest future regulations.

https://www.corning.com/media/worldwide/cet/documents/sae2006-01-0030.pdf

Diesel Emission Control in Review

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir and Pt.

Transition metal/zeolite scr catalysts

Pd supported on various zeolites has been found to be able to adsorb NO at temperatures below 200 °C with high storage efficiency and capacities in a gas feed which simulate diesel engine exhaust conditions. Highly dispersed Pd at the exchange sites of the zeolites are believed to be the active site for the low temperature NO storage. Different framework structures of the zeolites significantly affect not only the NO storage capacity but also the NOx desorption temperature. These materials show high potential for low temperature NOx emission control.

Low Temperature NO Storage of Zeolite Supported Pd for Low Temperature Diesel Engine Emission Control

The role of pore size on the thermal stability of zeolite supported Cu SCR catalysts

A comparative study of N2O formation during the selective catalytic reduction of NOx with NH3 on zeolite supported Cu catalysts

A cold start catalyst is disclosed. The cold start catalyst is effective to adsorb NO x and hydrocarbons (HC) at or below a low temperature and to covert and release the adsorbed NO x and HC at temperatures above the low temperature. The cold start catalyst comprises a molecular sieve catalyst and a supported platinum group metal catalyst. The molecular sieve catalyst consists essentially of a noble metal and a molecular sieve. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst, and a method for treating exhaust gas from an internal combustion engine utilizing the cold start catalyst.

Hai-Ying Chen

Papers

Transition metal/zeolite scr catalysts

Low Temperature NO Storage of Zeolite Supported Pd for Low Temperature Diesel Engine Emission Control

The role of pore size on the thermal stability of zeolite supported Cu SCR catalysts

A comparative study of N2O formation during the selective catalytic reduction of NOx with NH3 on zeolite supported Cu catalysts

Cold start catalyst and its use in exhaust systems