SusChEM: New Ni Macrocyclic Catalysts for Solar Driven Carbon Dioxide Reduction

Purdue University, West Lafayette IN

Investigators

Abstract

In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Tong Ren of the Department of Chemistry at Purdue University is studying new complexes of the element, nickel, that can be used to catalyze reactions of carbon dioxide using sunlight. Professor Ren is synthesizing cyclic organic molecules that will bind to the nickel atom and remain stable during the course of the reaction. These product molecules are then being incorporated into solar cells. Professor Ren is providing a high level of level of interdisciplinary education and training for undergraduate and graduate students in chemical science, with an emphasis on broadening the participation of groups that are underrepresented in STEM disciplines. He and his students are also designing K-12 level laboratory teaching modules that teach elements of sustainable science and technology. Professor Ren is synthesizing macrocycle complexes of nickel with the aim of discovering ones that are among the best catalysts for carbon dioxide reduction. Nickel and cobalt macrocyclic complexes are among the best catalysts for carbon dioxide reduction, yet their performances, both over-potential and catalytic turnover, remain to be desired for large scale application. Initial experiments are focusing on improving both the carbon dioxide binding to the metal center and the stability of the complexes. To accomplish this aim, Professor Ren is introducing various substituents on the carbon atoms of the macrocyle with the objective of tuning the conformation of complex. He is also examining ways to stabilize carbon dioxide bound intermediates and reduce activation barriers through the introduction of pyridyl and proton-donor substituents. Optimized catalysts are being incorporated into photocells with a p-NiO photocathode that perform solar-driven carbon dioxide reduction. Professor Ren is working with Purdue's Science Express Program in bringing modern laboratory experiments to rural high schools across Indiana.