Dynamic piezocatalyst system

Patent metadata

Field	Value
Publication number	US-2021218034-A1
Application number	US-202016742383-A
Country	US
Kind code	A1
Filing date	Jan 14, 2020
Priority date	Jan 14, 2020
Publication date	Jul 15, 2021
Grant date	—

Abstract

Methods are provided for tailoring multi-step chemical reactions having competing elementary steps using a strained catalyst. In various aspects, a layered piezo-catalytic system is provided, and may include a metal catalyst overlayer disposed on a piezo-electric substrate. The methods include applying a voltage bias to the piezo-electric substrate of the piezo-catalytic system resulting in a strained catalyst having an altered catalytic activity as a result of one or both of a compressive stress and tensile stress. The methods include exposing reagents for at least one step of the multi-step chemical reaction to the strained catalyst, and catalyzing the at least one step of the multi-step chemical reaction. In various aspects, the methods may include using an oscillating voltage bias applied to the piezo-electric substrate.

First claim

What is claimed is:

1 . A method for tailoring a multi-step chemical reaction having competing elementary steps, the method comprising:
providing a layered piezo-catalytic system; applying a voltage bias to the piezo-catalytic system resulting in a strained metal catalyst having an altered catalytic activity; exposing reagents for at least one step of the multi-step chemical reaction to the strained metal catalyst; and catalyzing the at least one step of the multi-step chemical reaction.

2 . The method for tailoring a multi-step chemical reaction having competing elementary steps according to claim 1 , wherein the layered piezo-catalytic system comprises a metal catalyst overlayer disposed on a piezo-electric substrate.

3 . The method for tailoring a multi-step chemical reaction having competing elementary steps according to claim 2 , wherein applying the voltage bias to the piezo-catalytic system comprises providing an oscillating voltage bias to the piezo-electric substrate.

4 . The method for tailoring a multi-step chemical reaction having competing elementary steps according to claim 2 , wherein the metal catalyst overlayer comprises a metal selected from the group consisting of: Pt, Pd, Au, Ag, Ir, Os, Ru, Fe/K + , Pd—Ag, Pd—Au, platinum nanoalloys, and platinum group metal (PGM) alloys.

5 . The method for tailoring a multi-step chemical reaction having competing elementary steps according to claim 1 , wherein the multi-step chemical reaction comprises a reaction selected from the group consisting of: aqueous electrocatalysis, steam reforming of methane, CO oxidation, NO oxidation, ammonia synthesis, and acetylene hydrogenation.

6 . A method for tailoring an aqueous electrocatalysis reaction, the method comprising:
providing a layered piezo-catalytic system including a metal catalyst overlayer disposed on a piezo-electric substrate; applying a voltage bias to the piezo-electric substrate resulting in a strained catalyst having an altered catalytic activity; exposing reagents for the aqueous electrocatalysis reaction to the strained catalyst; and catalyzing at least one step of the aqueous electrocatalysis reaction.

7 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein the metal catalyst overlayer comprises a metal selected from the group consisting of: Pt, Pd, Au, Ag, and Ir.

8 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein metal catalyst overlayer comprises a platinum alloy selected from the group consisting of: Pt 2 Co, Pt 3 Ni, Pt 3 Sc, Pt 3 Y, and Pt/Ru.

9 . The method for tailoring an aqueous electrocatalysis reaction according to claim 8 , wherein the platinum alloy comprises Pt 3 Ni.

10 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein the piezo-electric substrate comprises a material selected from the group consisting of: BaTiO 3 , LaTaO 3 , SrTiO 3 , SiO 2 , and LiTaO 3 .

11 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein the piezo-electric substrate comprises a material selected from the group consisting of: PbZrO 3 , PbTiO 3 , AlN, and KNbO 3 .

12 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein applying the voltage bias to the piezo-catalytic system comprises:
providing a first voltage bias to the piezo-electric substrate for a first predetermined period of time; and providing a second voltage bias to the piezo-electric substrate for a second predetermined period of time.

13 . The method for tailoring an aqueous electrocatalysis reaction according to claim 12 , wherein the second voltage bias is different from the first voltage bias.

14 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein applying the voltage bias to the piezo-electric substrate comprises providing an oscillating voltage bias to the piezo-electric substrate.

15 . The method for tailoring an aqueous electrocatalysis reaction according to claim 14 , wherein providing the oscillating voltage bias to the piezo-electric substrate results in the strained catalyst changing from being exposed to alternating compressive and tensile stresses.

16 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein the layered piezo-catalyst system comprises:
a first metal catalyst overlayer disposed on a first piezo-electric substrate; and a second metal catalyst overlayer disposed on a second piezo-electric substrate, further wherein applying the voltage bias to the piezo-electric substrate comprises: providing a first voltage bias to the first piezo-electric substrate for a first predetermined period of time; and providing a second voltage bias to the second piezo-electric substrate for a second predetermined period of time.

17 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein the aqueous electrocatalysis reaction comprises a reaction selected from the group consisting of: an oxygen reduction reaction (ORR), an oxygen evolution reaction (OER), a hydrogen evolution reaction (HER), and an electrochemical direct carbon dioxide reduction reaction (CO 2 RR).

18 . The method for tailoring an aqueous electrocatalysis reaction according to claim 6 , wherein the metal catalyst overlayer is provided having a thickness of from about 5 nm to about 10 nm.

19 . A metal catalyst comprising:
a substrate having a first region and a second region; a first metal disposed on a surface of the first region of the substrate; and a second metal disposed on a surface of the second region of the substrate, the second metal comprising a work hardened metal that has been subjected to at least one strain force resulting in active sites created therein, the active sites having a unique reactivity relative to the first, unstrained metal disposed on the first region of the substrate.

Assignees

• Toyota Res Inst Inc

Inventors

• Montoya Joseph Harold
• Aykol Muratahan

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M4/9025

  Oxides specially used in fuel cell operating at high temperature, e.g. SOFC · CPC title

• H01M4/8803 Primary

  Supports for the deposition of the catalytic active composition (H01M4/90 takes precedence) · CPC title

• H01M4/9033

  Complex oxides, optionally doped, of the type M1MeO3, M1 being an alkaline earth metal or a rare earth, Me being a metal, e.g. perovskites · CPC title

• H01M4/92

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title