Selective CO2 Conversion with Novel Copper Catalyst

Abstract

The present disclosure provides hierarchical CuO-derived inverse opal (CuO—IO) electrocatalyst compositions, their synthesis, and their application to selectively convert CO 2 into carbon monoxide (CO). The electrocatalyst compositions have a three-dimensional interconnected CuO backbone in hexagonal arrangement. In one embodiment, the compositions have an inverse structure of poly (methyl methacrylate) (PMMA) latex opal. In one embodiment, the electrocatalyst composition inverse-opal structure is comprised of copper-oxide nanoparticles having an average mean diameter ranging from about 15 to about 20 nm. In another embodiment, the compositions have an average cavity size of 175 to 185 nm.

What is claimed is: 
     
         1 . A method for the synthesis of an electrocatalyst composition, the method comprising:
 providing a polymethylmethacrylate latex;   infiltrating the polymethylmethacrylate latex with a copper precursor; and,   annealing the infiltrated polymethylmethacrylate latex to provide an electrocatalyst having an inverse opal structure.   
     
     
         2 . A method for electrochemical conversion of CO 2  to CO comprising:
 providing a working electrode comprising an electrocatalyst, wherein the electrocatalyst comprises a 3D interconnected porous copper inverse-opal structure;   applying a negative potential to the working electrode;   contacting the working electrode with CO 2 , wherein the CO 2  is reduced to CO.   
     
     
         3 . The method of  claim 2  wherein the electrocatalyst has an average cavity size ranging from about 175 to about 185 nm. 
     
     
         4 . The method of  claim 2  wherein the inverse-opal structure has a hexagonal structure. 
     
     
         5 . The method of  claim 2  wherein the inverse-opal structure is a negative replica of poly (methyl methacrylate) opal. 
     
     
         6 . The method of  claim 2  wherein the 3D interconnected porous copper inverse-opal structure comprises nanoparticles with an average mean diameter ranging from about 15 to about 20 nm. 
     
     
         7 . The method of  claim 2  wherein the method has a Faradaic efficiency greater than about 65% at −0.7 V vs. RHE. 
     
     
         8 . The method of  claim 7  wherein the Faradaic efficiency is greater than about 70% at −0.6 V vs. RHE. 
     
     
         9 . The method of  claim 2  wherein the CO 2  is converted to CO with a CO to H 2  selectivity greater than about 80% at −0.8 V vs. RHE. 
     
     
         10 . The method of  claim 9  wherein the CO to H 2  selectivity is greater than about 90% at −0.7 V vs. RHE. 
     
     
         11 . The method of  claim 2 , wherein the inverse-opal structure has a hexagonal structure; wherein the inverse-opal structure is a negative replica of poly (methyl methacrylate) opal; wherein the electrocatalyst has an average cavity size ranging from about 175 to about 185 nm; wherein the method has a Faradaic efficiency greater than about 70% at −0.6 V vs. RHE; and wherein the method the CO 2  is converted to CO with a CO to H 2  selectivity up to about 90% at −0.7 V vs. RHE. 
     
     
         12 . The method of  claim 2  wherein the electrocatalyst comprises copper in a +2 oxidation state in the providing step. 
     
     
         13 . The method of  claim 2  wherein the electrocatalyst comprises copper in a 0 oxidation state when the negative potential is applied to the working electrode.