CN113668002B - Method for preparing acetone by using formic acid - Google Patents

Abstract

The invention discloses a method for preparing acetone with formic acid, which uses 0.1-0.7mol·L ^-1 formic acid solution as the electrolyte, metal lead sheet as the cathode, and an inert material as the anode. Electrolysis is carried out at -1.4～-1.7V _{vs. SCE} ; this method electrochemically reduces formic acid to acetone and ethanol, which has the characteristics of simple equipment, small footprint, simple process, and convenient operation. It is used in the preparation of C3 organic matter from C1 organic matter It has good theoretical and practical significance.

Description

A kind of method preparing acetone with formic acid

technical field

The invention relates to the technical field of organic chemical preparation, in particular to an electrochemical method for preparing acetone from formic acid.

Background technique

Formic acid, also known as formic acid, has the molecular formula HCOOH. Formic acid is a colorless liquid with a pungent smell. It is an important basic chemical raw material, an intermediate of chemical reactions and a carrier of renewable energy. It is widely used in industries such as pesticides, leather, dyes, medicine and rubber. Formic acid is a C1 organic compound, and its preparation method is relatively simple and easy. The industrial preparation mainly includes sodium formate method, methanol oxo synthesis method (also known as methyl formate method), formamide method, etc.

Acetone, also known as dimethyl ketone, is the simplest saturated ketone with the molecular formula CH ₃ COCH ₃ . It is a colorless and transparent liquid with a special pungent smell. Soluble in water and organic solvents such as methanol, ethanol, ether, chloroform, pyridine, etc., flammable, volatile, and relatively active in chemical properties. Acetone is a C3 organic matter and is an important raw material for organic synthesis. It is used in the production of epoxy resin, polycarbonate, plexiglass, medicine, pesticide, etc. It is an important raw material for isoprene rubber, methyl methacrylate, etc. It is also a good solvent, thinner, cleaning agent, extractant, etc. The production methods of acetone mainly include cumene method, isopropanol method, fermentation method, acetylene hydration method and propylene direct oxidation method, etc. At present, the industrial production of acetone is mainly based on the cumene method.

Because the electrochemical method has the advantages of simple equipment, small footprint, usually at room temperature, convenient operation, large or small production scale, few by-products, and high product selectivity, it is widely used in organic chemical industry, but there is no use of formic acid at present. A method for preparing acetone as a substrate reactant by an electrochemical method.

Contents of the invention

In order to solve the deficiencies in the prior art, the inventor provides an electrochemical method for preparing acetone from formic acid, which has the characteristics of simple process, convenient operation, and high selectivity of the products acetone and ethanol.

Specifically, the present invention provides a method for preparing acetone with formic acid, using formic acid as the base reactant, and preparing acetone by electrochemical method, the formic acid is electrochemically reduced to acetone and/or ethanol, and the reaction at the cathode is:

3HCOOH+10H ^{++ 10e-} → _CH3COCH3 + _{5H2O .}

Using 0.1～0.7mol·L ^-1 formic acid solution as the electrolyte, the metal lead sheet as the cathode, and the inert material as the anode, the electrolysis is carried out at the cathode electrolysis voltage of -1.4～-1.7V _{vs. SCE} relative to the saturated calomel electrode . Wherein, the sizes of the cathode and the anode are determined according to actual needs.

Further, the inert material is metal platinum sheet or graphite sheet.

The invention provides a method for preparing acetone by electrochemical method with formic acid as the base reactant, electrochemically reducing formic acid to acetone and ethanol, and every 3 mol of formic acid can be reacted to generate 1 mol of acetone, the process is simple, the operation is convenient, and the area is occupied The area is small, and it has good theoretical and practical significance in preparing C3 organic matter from C1 organic matter.

Detailed ways

The present invention will be described in further detail below by way of examples.

Example 1

In a 150mL electrolytic cell, add 100mL of 0.1mol L ^-1 HCOOH solution, use a 3cm×4cm lead sheet as the cathode, a 3cm×4cm platinum sheet as the anode, and a saturated calomel electrode as the reference electrode. Electrolyzed at 1.6V _{vs. SCE} for 10 hours, the faradaic efficiency of the product acetone is 5.47%, and there is no by-product ethanol.

Example 2

In a 150mL electrolytic cell, add 100mL of 0.3mol L ^-1 HCOOH solution, use a 3cm×4cm lead sheet as the cathode, a 3cm×4cm platinum sheet as the anode, and a saturated calomel electrode as the reference electrode. After electrolysis at 1.6V _{vs. SCE} for 10 hours, the Faradaic efficiency of the product acetone is 9.60%, and the Faradaic efficiency of the by-product ethanol is 0.90%.

Example 3

In a 150mL electrolytic cell, add 100mL of 0.7mol·L ^-1 HCOOH solution, use a 3cm×4cm lead sheet as the cathode, a 3cm×4cm platinum sheet as the anode, and a saturated calomel electrode as the reference electrode. The Faradaic efficiency of the product acetone was 2.18% and the Faradaic efficiency of the by-product ethanol was 2.12% after electrolysis at the cathodic electrolysis voltage -1.6V _{vs. SCE} for 10 hours.

Example 4

In a 150mL electrolytic cell, add 100mL of 0.3mol·L ^-1 HCOOH solution, use a 3cm×4cm lead sheet as the cathode, a 3cm×4cm platinum sheet as the anode, and a saturated calomel electrode as the reference electrode. The Faradaic efficiency of the product acetone was 4.77% and the Faradaic efficiency of the by-product ethanol was 1.80% after electrolysis at the cathodic electrolysis voltage -1.4V _{vs. SCE} for 10 hours.

Example 5

In a 150mL electrolytic cell, add 100mL of 0.3mol·L ^-1 HCOOH solution, use a 3cm×4cm lead sheet as the cathode, a 3cm×4cm platinum sheet as the anode, and a saturated calomel electrode as the reference electrode. The Faradaic efficiency of the product acetone was 2.55% and the Faradaic efficiency of the by-product ethanol was 0.18% after electrolysis at the cathodic electrolysis voltage -1.7V _{vs. SCE} for 10 hours.

Example 6

In a 150mL electrolytic cell, add 100mL of 0.3mol·L ^-1 HCOOH solution, use a 3cm×4cm lead sheet as the cathode, a 3cm×4cm platinum sheet as the anode, and a saturated calomel electrode as the reference electrode. The faradaic efficiency of the product acetone was 7.36% and the faradaic efficiency of the by-product ethanol was 2.74% after electrolysis at the cathodic electrolysis voltage -1.6V _{vs. SCE} for 7 hours.

Claims (2)

1. A process for preparing acetone from formic acid features that the solution is prepared from 0.1-0.7 mol of 8729L ^-1 The formic acid solution is taken as electrolyte, the metal lead sheet is taken as cathode, the inert material is taken as anode, and the cathode electrolysis voltage relative to the saturated calomel electrode is-1.4 to-1.7V _vs.SCE The electrolysis is carried out to electrochemically reduce formic acid to acetone, and the reaction at the cathode is as follows:

3HCOOH+10H ⁺ +10e ^- →CH ₃ COCH ₃ +5H ₂ O。

2. the method of claim 1, wherein the inert material is a metallic platinum sheet or a graphite plate.