Atom-economical reduction of carbon monoxide to methanol catalyzed by soluble transition metal complexes at low temperatures

Hydrocarbons and methanol are considered the preferred products of catalytic reduction of CO derived from clean natural gas. Atom-economical synthesis of methanol catalyzed by soluble transition metal complexes as single-site catalyst precursors was studied under mild reaction conditions. Methanol could be effectively synthesized at low temperatures (≤ 150°C) using the complexed Ni/alkali metal alkoxide/methanol/glyme catalyst system with high turnover numbers. The low operating temperature fell in the range where high conversion (> 90%) per pass of synthesis gas to methanol is thermodynamically allowed under a low operating pressure (< 5 MPa). The Ni system provided an excellent opportunity to establish a time-resolved structure/activity/product selectivity relationship under mild conditions. The base-activated Ni system achieved high per pass CO conversion and high methanol selectivity that together impart atom-economy to the methanol synthesis reaction. The atom-economy combined with observed high turnover numbers might result in a process that produces methanol cheaply enough to be considered as a feedstock.