NU 2015-019

Inventor

Justin Notestein

Short Description

A catalytic material that photocatalytically synthesizes H2O2 in situ for a subsequent in situ thermocatalytic reaction

Abstract

Industrial chemical manufacturing is an enormous market with projections for continued growth. The catalyst sector alone is currently a $13Bn market. Some industrial chemical production uses hydrogen peroxide (H2O2) as an oxidant carrying out important oxidative and hydroxylation chemistry. However, there is risk and cost associated with the storage and transportation of H2O2industrially. Therefore, a catalyst that can both produce and subsequently utilize H2O2 to carry out these chemical processes is a greener, inexpensive and safer alternative. Northwestern researchers have developed a novel catalytic material that efficiently synthesizes an important oxidant, H2O2, and uses it to carry out a subsequent chemical reaction in a simple two-step process. This catalyst consists of metal and metal oxides and has two significant uses for industrial processes: (1) it aids in generating H2O2 through photochemistry; and (2) it utilizes this H2O2 product to carry out important oxidation organic reactions through thermochemical processes. Not only has this catalyst been shown to be more efficient and simple than currently available catalysts, but it also has the benefit of being able to produce H2O2 that can either be isolated at high yields or subsequently consumed to carry out efficient oxidation chemical reactions. The material itself consists of engineered particles of TiO2 partially coated with silica to synthesize H2O2. They have successfully produced equivalent to 21 mM H2O2 g-1¬?h-1, which is 6 times greater than the best-performing photocatalysts. The in situ production of H2O2 allows immediate access to nearby thermocatalysts (primarily Ti, Nb and Ta-based) to perform an alkene epoxidation reaction. To date, reactions proceed with greater than 95% selectivity, and localized production of H2O2 on the nano-scale results in enhanced epoxidation activity when compared to analogous examples where H2O2 is continuously added over the course of the reaction. The engineered particle synthesis strategy is simple and agile, such that the photocatalyst and thermal catalyst can be independently tuned and optimized for varied applications with a single catalytic platform.

Applications

• Industrial Chemical Manufacturing:
• Propylene glycol (use for building materials, antifreeze lubricants, pharmaceuticals, food additives);
• Polyols (use for polyurethane);
• Phenol (use for drugs, dyes);
• H2O2 itself can be used for disinfecting, bleaching agent, food production
• Many other products

Advantages

• Simple & agile system
• Elimination of risk associated with H2O2 storage and transportation
• Cost savings related to capital and operation associated with H2O2 use
• Improved in situ photocatalytic activity:
• 6x greater production of H2O2
• > 95% selectivity of catalyst reactions
• Elimination of expensive purification & concentration steps
• Enhanced secondary thermocatalytic activity (e.g., epoxidation)

Publications

Thornburg NE, Thompson AB and Notestein JM (2015). Periodic Trends in Highly Dispersed Groups IV and V Supported Metal Oxide Catalysts for Alkene Epoxidation with H2O2. American Chemical Society Catalysis, 5: 5077-5088.

IP Status

Pending US and PCT Patents on composition of matter and methods of use.