In a new study published in JACS Au, Osaka University researchers report having developed a single-crystal cobalt phosphide nanorod catalyst that offers a more effective alternative to conventional cobalt catalysts. Their catalyst could have significant implications for industries that rely on such catalysts to produce polymers, dyes, and pharmaceuticals through reductive amination.
Reductive amination refers to the chemical reaction that converts carbonyl compounds into amines. This reaction is necessary for many industrial processes but requires non-precious metal catalysts such as cobalt and nickel sponges that have particular limiting factors (sensitive to air, need high H2 pressures). For this reason, scientists have been attempting to develop alternative catalysts that are not as limited. Now the Osaka University team has succeeded in doing just that for a cobalt catalyst - by way of the addition of phosphorus.
"Our nanorod is the first metal-phosphide catalyst that has been used for reductive amination, as well as being the first cobalt catalyst that is effective at atmospheric pressure," study first author Min Sheng explains. "Furthermore, our catalyst showed the highest turnover number of all homogeneous and heterogeneous non-precious metal catalysts tested for the same reaction."
Having demonstrated the high activity of the catalyst retained after multiple uses, the researchers are confident that their catalyst will change the way chemical reactions are carried out in industries.
"We expect our nanorod catalyst to make a significant contribution to the cost and energy-efficient production of amines," says study corresponding author Takato Mitsudome. "But beyond this, we believe phosphorus-alloying has the potential to enhance the catalysis for many other organic reactions, leading to greener and more sustainable processes that improve productivity, conserve energy resources, and avoid the reliance on hazardous compounds while protecting our environment."