Bimetallic Catalysts for CO2 Hydrogenation and H2 Generation from Formic Acid and/or Salts Thereof
AssigneeNational Institute of Advanced Industrial Science and Technology (AIST)
InventorsJonathan F. Hull, Yuichiro Himeda, Etsuko Fujita, James T. Muckerman
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Abstract
The invention relates to a ligand that may be used to create a catalyst including a coordination complex is formed by the addition of two metals; Cp, Cp* or an unsubstituted or substituted π-arene; and two coordinating solvent species or solvent molecules. The bimetallic catalyst may be used in the hydrogenation of CO2 to form formic acid and/or salts thereof, and in the dehydrogenation of formic acid and/or salts thereof to form H2 and CO2.
Claims40
A ligand represented by formula I below:
- wherein X is independently OH, SH, or NH2.
A catalyst of formula II below:
- wherein:
- X is independently OH, SH, or NH2;
- M independently represents Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru, or Os;
- Y independently represents a coordinating solvent species or solvent molecule selected from the group consisting of halide, water, hydroxyl, carbonyl, acetonitrile, dimethylformamide, and dimethylsulfoxide;
- L independently represents Cp, Cp*, or an unsubstituted or substituted n-arene;
- m and c independently represent integers from 1 to 6;
- n represents 0, +1, +2, +3, +4, +5, or +6;
- a represents an integer from 0 to 6;
- B represents an anion;
- and
- m×n=a×c.
A method of hydrogenating CO2 to form formic acid and/or a salt thereof comprising reacting CO2 and H2 in water in the presence of a catalyst of formula II below and a base:
- wherein:
- X is independently OH, SH, or NH2;
- M independently represents Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru, or Os;
- Y independently represents a coordinating solvent species or solvent molecule selected from the group consisting of halide, water, hydroxyl, carbonyl, acetonitrile, dimethylformamide, and dimethylsulfoxide;
- L independently represents Cp, Cp*, or an unsubstituted or substituted n-arene;
- m and c independently represent integers from 1 to 6;
- n represents 0, +1, +2, +3, +4, +5, or +6;
- a represents an integer from 0 to 6;
- B represents an anion;
- and
- m×n=a×c.
A method of dehydrogenating formic acid and/or a salt thereof to form H2 and CO2 comprising reacting formic acid and/or a salt thereof in the presence of a catalyst of formula II below:
- wherein:
- X is independently OH, SH, or NH2;
- M independently represents Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru, or Os;
- Y independently represents a coordinating solvent species or solvent molecule selected from the group consisting of halide, water, hydroxyl, carbonyl, acetonitrile, dimethylformamide, and dimethylsulfoxide;
- L independently represents Cp, Cp*, or an unsubstituted or substituted n-arene;
- m and c independently represent integers from 1 to 6;
- n represents 0, +1, +2, +3, +4, +5, or +6;
- a represents an integer from 0 to 6;
- B represents an anion;
- and
- m×n=a×c.
A method of reversibly storing hydrogen, the method comprising the steps of:
- a) providing H2 and CO2 in water;
- b) adjusting the pH to a minimum of 5 at a temperature and pressure sufficient to produce formic acid and/or a salt thereof;
- and
- c) adjusting the pH to a maximum of 8 at a temperature and pressure sufficient to dehydrogenate the formic acid and/or a salt thereof to produce H2 and CO2;
- wherein steps b) and c) are conducted in the presence of a catalyst of formula II below:
- wherein:
- X is independently OH, SH, or NH2;
- M independently represents Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru, or Os;
- Y independently represents a coordinating solvent species or solvent molecule selected from the group consisting of halide, water, hydroxyl, carbonyl, acetonitrile, dimethylformamide, and dimethylsulfoxide;
- L independently represents Cp, Cp*, or an unsubstituted or substituted n-arene;
- m and c independently represent integers from 1 to 6;
- n represents 0, +1, +2, +3, +4, +5, or +6;
- a represents an integer from 0 to 6;
- B represents an anion;
- and
- m×n=a×c.
Dependencies are inferred from the claim text.