Biomass transition metal hydrogen-evolution electrocatalysts and electrodes
A catalytic composition from earth-abundant transition metal salts and biomass is disclosed. A calcined catalytic composition formed from soybean powder and ammonium molybdate is specifically exemplified herein. Methods for making the catalytic composition are disclosed as are electrodes for hydrogen evolution reactions comprising the catalytic composition.
1. A catalytic composition, said composition comprising a nanocrystalline structure comprising a transition metal carbide having an average grain size between 1 nm and 100 nm and a transition metal nitride having an average grain size between 1 nm and 100 nm.
2. The catalytic composition of claim 1 , wherein the metal carbide and the metal nitride nanocrystals have a weight ratio between 0.1:1 and 10:1.
3. The catalytic composition of claim 1 , wherein the composition comprises pores having an average pore size between 20 nm and 250 nm.
4. The catalytic composition of claim 1 , wherein the metal is selected from the group consisting of Mo, W, Ti, Co, Ni, Cu, Fe, and mixtures thereof.
5. The catalytic composition of claim 1 , wherein the metal nitride is γ-Mo 2 N and the metal carbide is β-Mo 2 C.
6. The catalytic composition of claim 5 , wherein the β-Mo 2 C crystals are orthorhombic and the γ-Mo 2 N crystals are tetragonal.
7. A method for preparation of a catalytic composition, said method comprising:
mixing a biomass with a transition metal in a suitable solvent to create a dispersed suspension of the biomass with the transition metal;
drying the suspension; and
calcining the dried suspension to form the catalytic composition.
8. The method of claim 7 , wherein the transition metal comprises one or more transition metal salts.
9. The method of claim 8 , wherein the transition metal salt is selected from the group consisting of Mo, W, Ti, Co, Ni, Cu, Fe, and mixtures thereof.
10. The method of claim 9 , wherein the transition metal salt is selected from the group consisting of Mo salts, W salts, and mixtures thereof.
11. The method of claim 10 , wherein the transition metal salt is a Mo salt.
12. The method of claim 11 , wherein the Mo salt is ammonium molybdate.
13. The method of claim 7 , wherein calcination takes place in an inert atmosphere.
14. The method of claim 7 , wherein the biomass is selected from the group consisting of soybean, peanut, chickpea, broad bean, cowpea, alfalfa, lentil, and mixtures thereof.
15. The method of claim 7 , wherein the biomass comprises greater than 10% protein.
16. The method of claim 7 , comprising a biomass to transition metal salt weight ratio is between 0.1:1 and 10:1.
17. A catalytic composition manufactured by a process of calcining biomass in the presence of one or more transition metal salts.
18. The catalytic composition of claim 17 , wherein the biomass is selected from the group consisting of soybean, peanut, chickpea, broad bean, cowpea, alfalfa, lentil, and mixtures thereof.
19. The catalytic composition of claim 17 , wherein the biomass comprises greater than 10% protein.
20. The catalytic composition of claim 17 , wherein the transition metal salt is selected from the group consisting of salts of Mo, W, Ti, Co, Ni, Cu, Fe, and mixtures thereof.
21. The catalytic composition of claim 20 , wherein the transition metal salt is selected from the group consisting of Mo salts, W salts, or mixtures thereof.
22. The catalytic composition of claim 21 , wherein the transition metal salt is a Mo salt.
23. The catalytic composition of claim 17 , comprising a biomass to transition metal salt weight ratio is between 0.1:1 and 10:1.
24. The catalytic composition of claim 17 , wherein the transition metal salt is ammonium molybdate.
25. A method for forming an electrode, said method comprising depositing the suspension of biomass and transition metal onto a solid support to form a coated solid support, drying the coated support to remove said solvent, and thereafter subjecting the coated support to calcination.
26. The method of claim 25 , further comprising repeating said depositing and drying steps wherein depositing the suspension occurs more than once, each time followed by drying.
27. The method according to claim 25 , wherein the solid support is selected from the group consisting of carbon paper, metallic mesh, glass, graphene, or carbon cloth.
28. An electrode comprising a catalytic composition, said composition comprising a transition metal carbide and a transition metal nitride coated onto a solid support and calcined thereon.
29. The electrode according to claim 28 , wherein the transition metal carbide is β-Mo 2 C and the transition metal nitride is γ-Mo 2 N.
30. The electrode according to claim 28 , wherein the solid support is graphene.