Manganese oxide nanoparticle carbon microparticle electrocatalyst and method of making from albizia procera leaf

Patent metadata

Field	Value
Publication number	US-2021095384-A1
Application number	US-201916589711-A
Country	US
Kind code	A1
Filing date	Oct 1, 2019
Priority date	Oct 1, 2019
Publication date	Apr 1, 2021
Grant date	—

Abstract

A method for making an electrocatalyst containing manganese oxide nanoparticles present on carbon obtained from Albizia procera (MnOxNPs-C) for electrochemical water oxidation. The method includes a thermal decomposition and forms a product with specific morphological variations, including crystalline structure, elemental composition, and chemical compatibility. The manganese oxide nanoparticles are well dispersed over the carbon. The amount of manganese oxide nanoparticles increases by increasing the amount of precursor. Single-phase formation of the Mn3O4, and Mn3O4 along with MnO phase occurs at low and high amount of the precursor materials, respectively. The electrocatalyst can be used for the purpose electrolytic water splitting.

First claim

1 : An electrocatalyst, comprising:
manganese oxide nanoparticles supported on carbon microparticles, wherein the manganese oxide nanoparticles are in the form of crystallites having an average diameter in the range of 5-25 nm, and the carbon microparticles are derived from Albizia procera leaves and have an average longest dimension in the range of 100-300 μm.

2 : The electrocatalyst of claim 1 , wherein the manganese oxide nanoparticles have an average longest dimension in the range of 10 nm to 15 nm.

3 : The electrocatalyst of claim 1 , wherein the thickness of the carbon microparticles is less than 10 μm.

4 : The electrocatalyst of claim 1 , wherein the manganese oxide nanoparticles have peaks in the XRD at 2(θ) Bragg angles of 37±1° and 42±1°.

5 : The electrocatalyst of claim 1 , wherein the Mn:C molar ratio is from 10:1 to 1:10.

6 : The electrocatalyst of claim 1 , wherein the Mn:C molar ratio is from 5:1 to 1:1.

7 : An electrode, comprising:
an electrically conductive substrate coated with the electrocatalyst of claim 1 , wherein the electrode has a current density in the range of 6-18 mA/cm 2 at 1.5 V and an over potential in the range of 800-900 mV at 5 mA/cm 2 in 0.1 NaOH.

8 : The electrode of claim 7 , wherein the electrocatalyst is present on the surface of the electrode in an amount in the range of 0.2-10 mg/cm 2 .

9 : The electrode of claim 8 , wherein the BET surface area of the electrode is in the range of 100 to 200 m 2 g −1 .

10 : The electrode of claim 9 , wherein the electrically conductive substrate is selected from the group consisting of glassy carbon, graphite, gold, platinum, silver, iron, copper, and aluminum.

11 : An electrochemical cell, comprising:
a cathode electrode, an anode electrode, reference electrode, and an electrolyte, wherein at least one of electrodes is the electrode of claim 7 .

12 : The electrochemical cell of claim 11 , wherein the electrolyte is an aqueous alkali metal hydroxide or a mineral acid at a concentration in the range of 0.1 to 2.0 M.

13 : The electrochemical cell of claim 11 , wherein the electrolyte is 0.5 M aqueous sulfuric acid.

14 : A method of producing hydrogen and oxygen from water, comprising:
applying an electric potential to water in the electrochemical cell of claim 11 , and collecting the hydrogen at the cathode electrode, and the oxygen at the anode electrode.

15 : The method of claim 14 , wherein an electric potential is applied to at least one of the electrodes; and
the hydrogen is formed by electrolytically splitting water.

16 : A method of making the electrocatalyst of claim 1 , comprising:
preparing the carbon microparticles by drying and pulverizing Albizia procera leaf, then heating the dried pulverized leaf to a temperature in the range of 600-1,200 C.°; mixing a solution/suspension of the carbon microparticles with a solution/suspension of a manganese compound then removing the solvent to form a dry mixture; heating the dry mixture at temperature in the range of 200-600 C.° in an inert atmosphere.

17 : The method of claim 16 , wherein the manganese compound is manganese acetate.

18 : The method of claim 16 , wherein the carbon microparticles and the manganese compound are solutions/suspensions in ethanol.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Aziz Md Abdul
• Shah Syed Shaheen
• Yamani Zain Hassan

Classifications

• C25B11/054

  Electrodes comprising electrocatalysts supported on a carrier · CPC title

• C25B11/079

  Manganese dioxide; Lead dioxide · CPC title

• C25B11/065

  Carbon · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• C25B1/04

  by electrolysis of water · CPC title