Cerium-doped zeolitic imidazolate framework (cey-zif-zni) based electrode for electrocatalytic reduction of co2 to co

Abstract

An electrode includes a transparent glass substrate, and a cerium-doped zeolitic imidazolate framework (Cey-ZIF-zni) material at least partially covering a surface of the transparent glass substrate. A method of making the Cey-ZIF-zni. A method of electrochemical carbon dioxide (CO2) reduction (CO2RR) using the electrode.

1 : An electrode, comprising:
 a transparent glass substrate;   a cerium-doped zeolitic imidazolate framework (Ce y -ZIF-zni) material at least partially covering a surface of the transparent glass substrate;   wherein the cerium-doped zeolitic imidazolate framework (Ce y -ZIF-zni) material is at least one of an excess solvent deposition (ESD) Ce y -ZIF-zni material (Ce y -ZIF-zni-X), and a chemical vapor deposition (CVD) Ce y -ZIF-zni material (Ce y -ZIF-zni-CVD);   wherein y is between 0.01 and 1 inclusive;   wherein the Ce y -ZIF-zni-X comprises flake-like particles having an average particle size of 0.5 to 5.5 micrometers (μm);   wherein the Ce y -ZIF-zni-CVD comprises rod-like particles having an average particle size of 1 to 6 μm; and   wherein the Ce y -ZIF-zni material is uniformly disposed on the surface of the transparent glass substrate.   
     
     
         2 : The electrode of  claim 1 , wherein the transparent substrate is a glass substrate selected from the group consisting of a fluorine doped tin oxide (FTO) glass substrate, a tin doped indium oxide (ITO) glass substrate, an aluminum doped zinc oxide (AZO) glass substrate, a niobium doped titanium dioxide (NTO) glass substrate, an indium doped cadmium oxide (ICO) glass substrate, an indium doped zinc oxide (IZO) glass substrate, a fluorine doped zinc oxide (FZO) glass substrate, a gallium doped zinc oxide (GZO) glass substrate, an antimony doped tin oxide (ATO) glass substrate, a phosphorus doped tin oxide (PTO) glass substrate, a zinc antimonate glass substrate, a zinc oxide glass substrate, a ruthenium oxide glass substrate, a rhenium oxide glass substrate, a silver oxide glass substrate, and a nickel oxide glass substrate. 
     
     
         3 : The electrode of  claim 1 , wherein the Ce y -ZIF-zni-CVD has an average particle size of about 3.2 μm, and a lattice interatomic spacing of the (111) plane of about 0.28 nm. 
     
     
         4 : A method of making the electrode of  claim 1 , wherein the Ce y -ZIF-zni material is Ce y -ZIF-zni-X, the method further comprises:
 preparing the Ce y -ZIF-zni-X by:   mixing a zinc salt, an imidazole, and an alcohol to form a first mixture;   heating the first mixture thereby reacting the zinc salt with the imidazole to form a first ZIF-zni precursor in the first mixture;   removing the ZIF-zni precursor from the first mixture, washing and heating to form the ZIF-zni material;   mixing the ZIF-zni material, a cerium salt and the alcohol and drying to form a second mixture; and   heating the second mixture at a temperature of about 150° C. thereby generating cerium nanoparticles disposed on surfaces of the ZIF-zni material to form the Ce y -ZIF-zni-X;   wherein a weight ratio of the ZIF-zni material to the cerium salt is in a range of 20:1 to 1:1.   
     
     
         5 : The method of  claim 4 , wherein the zinc salt is at least one selected from the group consisting of zinc sulfate, zinc acetate, zinc citrate, zinc iodide, zinc chloride, zinc perchlorate, zinc nitrate, zinc phosphate, zinc triflate, zinc bis(trifluoromethanesulfonyl)imide, zinc tetrafluoroborate, and zinc bromide, or its hydrate, or a mixture of two or more of any of these. 
     
     
         6 : The method of  claim 4 , wherein the imidazole has a formula (I) 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , and R 3  are each independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted alkoxy, a hydroxyl, a halogen, a nitro, and a cyano. 
       
     
     
         7 : The method of  claim 4 , wherein the alcohol is at least one of methanol, ethanol, iso-propanol. 
     
     
         8 : The electrode of  claim 4 , wherein the ZIF-zni material has an average particle size of about 4.3 μm. 
     
     
         9 : The method of  claim 4 , wherein the cerium salt is at least one of cerium chloride, cerium nitrate, cerium ammonium nitrate, and cerium sulfate, or its hydrate, or a mixture of two or more of any of these. 
     
     
         10 : A method of making the electrode of  claim 1 , wherein the Ce y -ZIF-zni material is Ce y -ZIF-zni-CVD, the method further comprises:
 preparing the Ce y -ZIF-zni-CVD by:   mixing a zinc salt, an imidazole, and an alcohol to form a first mixture;   heating the first mixture thereby reacting the zinc salt with the imidazole to form a first ZIF-zni precursor in the first mixture;   removing the ZIF-zni precursor from the first mixture, washing and heating to form the ZIF-zni material; and   generating a cerium precursor vapor by heating a cerium salt, and passing the cerium precursor vapor in contact with the ZIF-zni material thereby generating cerium nanoparticles disposed in the lattices and surfaces of the ZIF-zni material to form the Ce y -ZIF-zni-CVD;   wherein a weight ratio of the ZIF-zni material to the cerium salt is in a range of 20:1 to 1:1.   
     
     
         11 : The method of  claim 10 , wherein the zinc salt is at least one selected from the group consisting of zinc sulfate, zinc acetate, zinc citrate, zinc iodide, zinc chloride, zinc perchlorate, zinc nitrate, zinc phosphate, zinc triflate, zinc bis(rifluoromethylsulfonyl)imide, zinc tetrafluoroborate, and zinc bromide, or its hydrate, or a mixture of two or more of any of these. 
     
     
         12 : The method of  claim 10 , wherein the imidazole has a formula (I) 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , and R 3  are each independently selected from the group consisting of a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted alkoxy, a hydroxyl, a halogen, a nitro, and a cyano. 
       
     
     
         13 : The method of  claim 10 , wherein the alcohol is at least one of methanol, ethanol, iso-propanol. 
     
     
         14 : The method of  claim 10 , wherein the cerium salt is at least one of cerium chloride, cerium nitrate, cerium ammonium nitrate, and cerium sulfate, or its hydrate, or a mixture of two or more of any of these. 
     
     
         15 : The method of  claim 10 , wherein the cerium salt is heated in a furnace at a heating rate of 1 to 4 degree Celsius per minute (° C. min −1 ) in an inert atmosphere until the temperature of the furnace reaches a temperature of about 200° C. 
     
     
         16 : A method of electrochemical carbon dioxide (CO 2 ) reduction (CO 2 RR), comprising;
 charging an electrolyte to an electrochemical cell comprising a working electrode, a counter electrode, and a reference electrode;   introducing a CO 2 -containing gas composition into the electrochemical cell containing the electrolyte and passing the CO 2 -containing gas composition through the electrolyte;   during the passing, simultaneously applying a potential between the working electrode and the counter electrode in the electrochemical cell via the electrolyte to form carbon monoxide (CO);   wherein the working electrode comprises the electrode of  claim 1 ; and