Modified copper-zinc catalysts and methods for alcohol production from carbon dioxide
The present disclosure provides catalysts, comprising: copper; zinc; one or more first elements selected from iron, nickel, or cobalt; aluminum; oxygen; optionally, one or more second elements selected from a Group V, VI, VII, VIII, IX, X, and XI metal (e.g., manganese, silver, niobium, zirconium, molybdenum, ruthenium, or palladium); and optionally, one or more Group IA metals, and wherein the first element is present in an amount of about 1 to about 40 wt. % (e.g., about 1 to about 10 wt. %, about 25 to about 40 wt. %, about 30 to about 40 wt. %, or about 35 to about 40 wt. %) of the total amount of the copper, zinc, first element, the optional second element, and the optional Group IA metal, and methods of using said catalyst in the production of ethanol and higher alcohols from carbon dioxide.
1 . A method for reducing CO 2 , comprising contacting a modified CZA catalyst with a feed mixture comprising CO 2 and a reductant gas at a reduction temperature and a reduction pressure, thereby providing a liquid product mixture, wherein the modified CZA catalyst comprises:
copper;
zinc;
one or more first elements being cobalt oxide, and optionally iron oxide;
aluminum;
oxygen; and
optionally, one or more second elements selected from a Group V, VI, VII, VIII, IX, X, and XI metal, and wherein:
(A) the first element is present in an amount of about 1 to about 40 wt. % of the total amount of the copper, zinc, the first element, and the optional second element;
(B) wherein the molar ratio of copper to zinc is from about 2 to about 4.
2 . The method of claim 1 , wherein the reductant gas is H 2 .
3 . The method of claim 1 , where the reductant gas is a hydrocarbon selected from CH 4 , ethane, propane, or butane.
4 . The method of claim 1 , wherein the reductant gas is, or is derived from, flare gas, waste gas, or natural gas.
5 . The method of claim 1 , wherein the feed mixture comprises less than 25% of CO, less than 20% of CO, less than 15% of CO, less than 10% of CO, less than 5% of CO, or less than 1% of CO.
6 . The method of claim 1 , wherein the feed mixture is substantially free of CO.
7 . The method of claim 1 , wherein the method is selective for ethanol.
8 . The method of claim 1 , wherein the liquid product mixture comprises less than about 50 ppm formaldehyde.
9 . The method of claim 1 , wherein the catalyst comprises iron at a molar ratio of about 0.5 to about 1.5 relative to copper.
10 . The method of claim 1 , wherein the catalyst comprises one or more Group IA metals.
11 . The method of claim 1 , wherein the catalyst comprises cobalt oxide, iron oxide, copper, zinc oxide, and alumina.
12 . The method of claim 1 , wherein the catalyst comprises:
copper at a molar ratio of about 2.5 relative to the iron;
zinc oxide at a molar ratio of about 1 relative to the iron; and
alumina at a molar ratio of about 0.35 relative to the iron.