New nickel catalyst fuses unrefined hydrocarbons and CO2 to obtain valuable compounds

Chemists have designed a nickel catalyst that easily transforms petroleum feedstocks into valuable compounds like fatty acids. The process is environmentally friendly, working at room temperature and atmospheric pressure, and also recycles carbon dioxide, contributing to the fight against climate change.

Fatty acids are key in several industrial processes like the manufacture of soaps, plastics such as nylon, and dyes. Experts estimate that the global market for these compounds could reach $20 billion in the next few years. Classical synthetic methods to obtain fatty acids often require toxic and hazardous reagents like carbon monoxide and extreme conditions of pressures and temperatures. Alternative methods like the derivatization of natural products are less dangerous, but lead to complicated mixtures of products that require complicated purification. Now, a team led by Prof. Rubén Martín at the Institute of Chemical Research of Catalonia (ICIQ) has synthesized a sustainable nickel catalyst that solves both problems. It leads to pure fatty acids from raw hydrocarbons and CO2, which is less toxic than carbon monoxide.

Unrefined mixtures of hydrocarbons, olefins, and other petroleum-derived feedstocks can now be easily transformed into fatty acids. Moreover, researchers discovered the selectivity of the reaction can be regulated with subtle temperature variations. Tuning temperature causes nickel to slide along the hydrocarbon chain, incorporating CO2 closer to the end of the chain when the conditions are colder, and vice-versa.

"This chemistry allows us to repurpose simple hydrocarbons and abundant CO2 to prepare a wide range of pure fatty acids under exceptionally mild conditions," explains Martín. "This method enables the selective incorporation of CO2 at specific sites while preserving the chiral integrity within the organic molecule," he adds.

"The combination of an Earth-abundant nickel catalyst and CO2 with the hydrocarbon feedstocks is a breakthrough in the production of fatty acids," explains Francisco Juliá, first author of the Nature paper. "Current methods rely on hazardous carbon monoxide and precious metal catalysts in high risk of supply disruption. This is a greener and more sustainable methodology that could have significant implications for the environment while alleviating economic concerns," he concludes.

More information:
phys.org/news/2017-05-nickel-c … ons-fatty-acids.html

Provided by Institute of Chemical Research of Catalonia