Process for making hydrogen peroxide
A process for making hydrogen peroxide directly from hydrogen and oxygen is disclosed. The process comprises reacting the gases in a solvent in the presence of a catalyst comprising a polymer-encapsulated transition metal. Polymer-encapsulated transition metal catalysts are easy to prepare and use, they are easy to recover and reuse, and they provide good conversions to hydrogen peroxide.
1 . A process which comprises reacting hydrogen and oxygen in a solvent in the presence of a catalyst comprising a polymer-encapsulated transition metal to produce hydrogen peroxide.
2 . The process of claim 1 wherein the transition metal is one or more metals selected from Groups 7 to 11.
3 . The process of claim 2 wherein the transition metal is selected from the group consisting of Fe, Co, Ni, Pd, Pt, Ru, Rh, Re, Au, and mixtures thereof.
4 . The process of claim 3 wherein the transition metal is Pd.
5 . The process of claim 3 wherein the transition metal is selected from the group consisting of Pd—Pt mixtures and Pd—Au mixtures.
6 . The process of claim 1 wherein the polymer is selected from the group consisting of polystyrenics, polyolefins, polyureas, polyacrylics, polyurethanes, polyesters, polyamides, fluorinated polymers, polysaccharides, polypeptides, polynucleotides, and mixtures thereof.
7 . The process of claim 6 wherein the polymer is polystyrene.
8 . The process of claim 7 wherein the polymer-encapsulated transition metal is produced by polymerizing styrene in an aqueous suspension in the presence of a transition metal source.
9 . The process of claim 6 wherein the polymer is a phosphorus-functionalized polystyrenic.
10 . The process of claim 1 wherein the solvent is selected from the group consisting of water, oxygenated hydrocarbons, and mixtures thereof.
11 . The process of claim 1 wherein the solvent is selected from the group consisting of water, C 1 -C 4 alcohols, carbon dioxide, and mixtures thereof.
12 . The process of claim 1 wherein the solvent is a mixture of methanol and water.
13 . The process of claim 12 performed in the presence of a protic acid.
14 . The process of claim 1 wherein the transition metal is supported prior to polymer encapsulation.
15 . The process of claim 14 wherein the support is selected from the group consisting of silicas, aluminas, carbons, zeolites, clays, and organic polymers.
16 . The process of claim 15 wherein the transition metal is palladium and the support is a titanium silicalite.
17 . The process of claim 16 wherein the titanium silicalite is TS-1.
18 . The process of claim 1 performed in the presence of a protic acid.
19 . The process of claim 18 wherein the protic acid is hydrogen bromide.
20 . The process of claim 18 wherein the protic acid is a mixture of hydrogen bromide and phosphoric acid.