International Partner Search

Innovation & Technology Offer

New noble metal-free catalyst for the production of propylene oxide

Country of Origin: Spain
Reference Number: TOES20190905001
Publication Date: 5 September 2019

Summary

A Spanish university has developed a new and cost-effective catalyst without noble metals to obtain propylene oxide (PO) from the selective oxidation of propylene. It does not make use of dangerous or highly contaminating agents, and does not produce high quantities of reaction by-products, showing a high selectivity towards PO. Catalyst manufacturing companies interested in the commercial exploitation of this technology via patent licensing or technical collaboration agreements are sought.

Description

Propylene oxide (PO) is a compound that presents a high reactivity and chemical specificity towards the formation of polymers. These properties make this compound useful as a prepolymer for the synthesis of polyurethanes, polyether, polyols and other polymers. It is estimated that more than 13 million tonnes of this chemical will be produced by 2020.



Nowadays, the industrial scale synthesis of PO is carried out using propylene as raw material, based on non-catalysed reactions in liquid phase using dangerous and highly polluting agents such as chlorine and hydrogen peroxide. In addition, these processes produce large quantities of by-products in the reaction. These by-products reduce the efficiency of the process and significantly increase the cost of the target product.



For these reasons, in recent years, the scientific community is focusing on the development of catalysts as a more sustainable alternative, which produce the minimum amount of reaction by-products, both in liquid and gas phases. In particular, there is a growing interest in performing the selective oxidation of propylene to generate PO in the gas phase, because the reagents used to carry out this reaction are less toxic and hazardous. 



In the latter case, there are several works in the literature with new heterogeneous catalysts that present good catalytic properties (propylene conversion and selectivity towards the PO) for the reaction of selective oxidation of propylene to PO in gas phase. Among these, the catalysts based on gold nanoparticles deposited on titanosilicates (Au/Ti-SiO2) stand out. However, their high cost is their main drawback. 



In this sense, a Spanish research group has developed a noble metal-free catalytic system for its use in the selective oxidation reaction from propylene to propylene oxide (PO), mainly using gas-phase H2/O2 mixtures. This system presents catalytic properties (in terms of propylene conversion, selectivity to PO and H2 efficiency), superior to catalysts based on noble metals such as gold.



This catalyst is composed of nickel nanoparticles dispersed on an inorganic silica-based support. The inorganic support, in powder form, is selected from silicate and titanosilicate.



The preparation of this catalytic system involves the following steps:

a) impregnation of the inorganic support with a nickel precursor (nickel nitrate) dissolved in water,

b) addition to the solution obtained in step (a) an alkaline substance to reach a pH of 9-11,

c) washing and filtering the suspension obtained in step (b) until reaching a neutral pH,

d) drying the product obtained in step (c).



While the inorganic support obtained in stage (a) is obtained through the following stages:

i. addition of the silica based precursor to a previous solution of urea and surfactant with acetic acid, 

ii. heating the product obtained in stage i to a temperature between 30 - 45 ºC for 15-25 h,

iii. removal of urea,

iv. calcination of the product obtained at iii between 500-600ºC for 5-7 hours.



This catalytic system has been used in selective oxidation reactions to obtain propylene oxide from propylene in gas phase, obtaining conversions higher than 7% with a selectivity towards the desired product above 90% using small amounts of Nickel and with high hydrogen efficiencies for the generation of propylene oxide.



This catalyst is useful for the selective oxidation reaction of propylene in the gas phase. Then, catalyst manufacturing companies interested in obtaining cost-effective catalysts based on non-noble metals (Ni) with a high selectivity towards propylene epoxide in the selective oxidation of propylene are sought. The Spanish university is open to discuss with interested companies different ways of commercial exploitation of the technology: patent licensing agreements or technical collaboration agreements to further develop the catalyst or to adapt it to the company’s needs.

Advantages and Innovations

The main innovative aspect of the catalytic system is that it is based on Nickel, presenting itself as a sustainable alternative for the industrial production of PO at low cost and without the use of noble metals.



The catalytic system described above has the following advantages:



- Free of noble metals, reducing the cost of the catalyst and therefore the overall cost of producing propylene oxide from propylene.

- Conversions and selectivities similar to those obtained with noble metals (specifically, gold) are obtained.

- It does not use dangerous or highly contaminating agents.

- No large quantities of by-products are produced in the reaction.

Stage Of Development

Under development/lab tested

Stage Of Development Comment

Samples in quantities of around 5-10 g can be prepared simply and reproducibly. Given the extremely simple nature of the experimental procedure (comprising a sol-gel process and an impregnation), it could be synthesized at pilot pre-plant scale and even up to pilot plant scale (1 kg of product) in a relatively simple way.

Requested partner

- Type of partner sought: Industries.

- Specific area of activity of the partner: Catalyst manufacturer.

- Task to be performed: Commercial exploitation of the technology via patent licensing agreement or technical collaboration agreement in order to further develop the technology, to adapt it to their needs, etc.