Methods, systems and catalysts for oxidizing carbon monoxide to carbon dioxide
Methods and catalyst compositions for oxidizing CO to CO 2 at low temperatures are disclosed. In one embodiment, a method of oxidizing CO to CO 2 may involve heating a gaseous mixture comprising at least CO and O 2 with a catalyst mixture comprising Pd disposed on a Mn 3 O 4 mesoporous support at a temperature of about 0° C. to about 60° C., and wherein the CO to CO 2 conversion rate is about 40% to about 100%.
1. A method to oxidize CO to CO 2 , the method comprising:
forming a mesoporous Mn 3 O 4 support, wherein the forming comprises:
mixing a triblock copolymer, a manganese salt, and a solvent to form a solution,
wherein the triblock copolymer is poly(ethyleneglycol)-poly(propyleneglycol)-poly(ethyleneglycol), poly(ethyleneimine)-poly(ethyleneglycol)-poly(ethyleneimine), poly(ethyleneglycol)-polyacetal-poly(ethyleneglycol), polyacetal-poly(ethyleneglycol)-polyacetal, or any combinations thereof;
evaporating the solution; and
calcining to form the mesoporous Mn 3 O 4 support;
contacting the mesoporous Mn 3 O 4 support with a Pd compound to form a reaction mixture;
contacting the reaction mixture with a reducing agent to form a catalyst mixture; isolating the catalyst mixture; and
contacting a gaseous mixture and the catalyst mixture at a temperature of about 0° C. to about 60° C., wherein the gaseous mixture comprises CO and O 2 , and
wherein the CO is converted to CO 2 at a conversion rate of about 40% to about 100%.
2. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting with the catalyst mixture that comprises at least one Pd nanoparticle disposed on at least a portion of the mesoporous Mn 3 O 4 support.
3. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting at a temperature of about 20° C. to about 30° C., and wherein the CO is converted to CO 2 at a conversion rate of about 80% to about 100%.
4. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting at a temperature of about 0° C. to about 10° C., and wherein the CO is converted to CO 2 at a conversion rate of about 40% to about 50%.
5. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting the gaseous mixture that further comprises N 2 , He, H 2 , Ar, or any combination thereof.
6. The method of claim 1 , wherein the method comprises a batch process or a continuous flow process.
7. The method of claim 6 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting in the continuous flow process, where the gaseous mixture is in contact with the catalyst mixture at a flow rate of about 40 mL per minute to about 60 mL per minute.
8. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting with the catalyst mixture that includes about 1 weight percent to about 5 weight percent of Pd.
9. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting with the catalyst mixture that includes the mesoporous Mn 3 O 4 support having an average pore diameter of about 1 nanometer to about 50 nanometer.
10. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting the gaseous mixture that further comprises water.
11. The method of claim 1 , wherein contacting the gaseous mixture and the catalyst mixture comprises contacting the gaseous mixture that includes about 1 volume percent to about 10 volume percent CO.
12. A method to make a Pd/Mn 3 O 4 catalyst, the method comprising:
forming Mn 3 O 4 support, wherein the forming comprises:
mixing a triblock copolymer, a manganese salt, and a solvent to form a solution, wherein the triblock copolymer is poly(ethyleneglycol)-poly(propyleneglycol)-poly(ethyleneglycol), poly(ethyleneimine)-poly(ethyleneglycol)-poly(ethyleneimine), poly(ethyleneglycol)-polyacetal-poly(ethyleneglycol), polyacetal-poly(ethyleneglycol)-polyacetal, or any combinations thereof;
evaporating the solution; and
calcining to form the Mn 3 O 4 support,
contacting the Mn 3 O 4 support with a Pd compound to form a reaction mixture, contacting the reaction mixture with a reducing agent to form a precipitate, and isolating the precipitate.
13. The method of claim 12 , wherein contacting the Mn 3 O 4 support with the Pd compound comprises contacting a mesoporous Mn 3 O 4 support.
14. The method of claim 12 , wherein mixing the triblock copolymer, the manganese salt, and the solvent comprises mixing the manganese salt selected from the group consisting of Mn(NO 3 ) 2 , MnCl 2 , MnBr 2 , MnF 2 , MnPO 4 , MnSO 4 , or any combination thereof.
15. The method of claim 12 , wherein evaporating the solution comprises heating the solution to a temperature of about 50° C. to about 80° C. for about 24 hours to about 96 hours.
16. The method of claim 12 , wherein calcining the Mn 3 O 4 support comprises heating the Mn 3 O 4 support to a temperature of about 300° C. to about 600° C. for about 30 minutes to about 6 hours.
17. The method of claim 12 , wherein contacting the Mn 3 O 4 support with the Pd compound comprises contacting with Na 2 PdCl 4 , H 2 PdCl 4 , K 2 PdCl 4 , (NH 4 ) 2 PdCl 4 , Pd(CH 3 COO) 2 , Pd(NO 3 ) 2 , PdSO 4 , or any combination thereof.
18. The method of claim 12 , wherein contacting with the reducing agent comprises contacting with hydrazine, NaBH 4 , KBH 4 , or any combination thereof.
19. The method of claim 12 , wherein isolating the precipitate comprises removing the precipitate from the reaction mixture by centrifugation, filtration, distillation, decantation, or any combination thereof.