A look at the types of nanomaterials currently being commerically applied to nanocatalysts for clean energy.
Nanomaterials are playing an increasingly important role in improving catalytic activity and selectivity for clean energy applications, in hydrogen and liquid fuel production and clean combustion. The increased surface-to-volume ratio at the nanoscale (typically 10-80 nanometers) increases specific catalytic activity, and nanomaterials possess unique properties that make them more effective than conventional catalysts. Nanostructured catalysts show potential for replacing Platinum, Rhodium, PGM and other metals tailored specifically for hydrogen production, oil and gas refining, GTL, cleantech, pollution control and automotive industries. Nanomaterial-enabled catalysts have for example, the potential to make automobile combustion up to 100% selective and therefore produce little or no toxic by-products. Companies are developing advanced catalysts applications including emissions control, energy efficiency, and the synthesis of chemicals and fuels. In the petroleum industry, Auterra produces nanoscale organometallic compounds as additives and catalysts. Auterra’s proprietary process, FlexDS is a novel, catalytic process that offers the disruptive ability to upgrade heavy-sour crude oil that enables producers and refiners to improve the quality of their oil and oil products by removing pollutants and increasing API gravity. Headwaters NanoKinetix Incorporated’s NxCat technology provides a method to control the structure of catalyst particles, thereby controlling their catalytic function. NxCat™ catalysts and technology can be used in: chemical and pharmaceutical manufacturing; fuel cells; NOx and VOC emissions reduction; water treatment/remediation; fillers and coatings; precious metal catalyst regeneration and other applications. Nanoscale catalysts are also being developed for converting coal or biomass into liquid fuels; capturing waste heat for vehicular air conditioning and other energy efficiency and co-generation applications; and for on-site synthesis of hydrogen peroxide. Other companies developing nanoscale catalysts for clean energy applications include include Nanostellar, Auterra Inc., Headwaters NanoKinetix Incorporated, BASF, Hybrid Catalysis BV, Hypercat ACP, Ilika plc and Nanocompound GmbH, Nisshin Engineering, Inc., and QID Nanotechnologies.
CNTs are used as catalyst supports. Advantages of using them include resistance to acid/basic media; the possibility to control porosity and surface chemistry; chemical inertness; easy recovery of precious metal and a large specific surface area. CNTs companies developing catalysts based on CNTs include Hyperion Catalysis and Unidym.
POSS catalysts can contain one or more covalently bonded reactive functionalities suitable for polymerization, grafting, surface bonding, or other transformations covering the generation of precise catalytic materials and catalyst supports. They range approximately 1-3nm in size and can be molecularly enlarged to cover applications from homogeneous catalysis via membrane catalyst retention to truly heterogeneous catalysis.
SRI International is developing fullerenes as efficient hydrogen-transfer catalyst supports. Fullerenes ability to catalyze hydrodealkylations makes them potentially useful for petroleum upgrading and fullerene soot is very effective in converting methane into higher hydrocarbons.
The drive for a fossil-fuel-alternative to produce hydrogen is of critical importance. Steam reforming of bio-oil including the gasification of coke deposits in the presence of water is seen as alternative to generate hydrogen gas. Nano cerium oxides unique catalytic behaviour makes it a strong candidate for catalysts in the production of hydrogen in fuel cells.
Metal oxide nanomaterial catalysts have been commercialized in diesel vehicle emissions control and other emission control products. Other products in the pipeline include catalysts for non-automotive applications such as hydrogen peroxide production, synthesis gas (syngas) reformation and waste-heat recovery systems. Companies such as Nanostellar and Headwaters NanoKinetix Inc. are working in these areas.
Nanoporous materials have found applications as catalysts and sorption media due to their large internal surface area. They are important for the seperation of polluting species and recovery of beneficial ones. They are also finding application in hydrogen storage.
Metal nanoparticles show high efficiency as catalysts in terms of selectivity, reactivity, and improved yields of products under environmentally benign reaction conditions. Their high surface-to-volume ratio provides a larger number of active sites per unit area compared to heterogeneous catalysts.
Nano-nickel has been found to promote reactions traditionally catalyzed by platinum. As well as costing four times less than platinum, nano-nickel has a greater catalytic activity. Nano-nickel has very high catalytic activity at small particle sizes, and is physically and chemically robust. Companies producing nano-nickel for catalysts include QuantumSphere.