At 353 K, cyclohexane molecular oxyacetic acid can be oxidized by N- hydroxyphthalimide catalyst in one step, and more than 95% selective oxidation products can be obtained.

Adipic acid is the main product with high conversion rate (about 78%).

This part of oxidation also recorded an annual turnover of 74%.

Keywords: adipic acid; One step oxidation; Catalyst; Oxidation of cyclohexane; N-hydroxy phthalimide; Free radicals; selectivity

1 。 introduce

A lot of research has been done

Formulate effective methods to oxidize unactivated

C-H bond, because of the importance of alkanes,

Substrate for industry and synthesis

Aspect [1-7]. Catalytic oxidation of alkanes has been

Explore the use of different oxidants [8], these reactions

Molecular oxygen [9] under mild conditions is

Because of its cheap availability and

Production water is the main harmless by-product.

However, cyclohexane oxide proved to be

The most effective all major industrial production processes [10].

At present, industrial cyclohexane oxidation is

Adipic acid goes through two steps. first step

And relates to oxidation of cyclohexane and cyclohexanone.

The pressure of cyclohexanol is about 423 K, 1-2 MPa.

Using soluble cobalt catalyst or catalyst-free, in

A liquid phase in which all cyclohexane is converted.

Less than 4%. At this low conversion rate

Selectivity of cyclohexene and cyclohexanone

(Household oil) can be optimized to 70-85% even if it is not much.

Peroxide products [165438+ 10/3]. Second step

Ka petroleum adipic acid involved in oxidation passed

Use nitric acid as a mild oxidant. by-product

The step of generate this gas includes nitrous oxide (N2O),

This shows that the global warming effect is 300 times.

More than carbon dioxide. Research is to improve

Two-step reaction selectivity. For example,

Furthermore, boric acid oxidizes the mixture.

Prove to be effective, thus making

The conversion of 10% and the selectivity of cyclohexane were 90%.

Oil stuck [14]. Murahashi et al. reported the oxidation phenomenon.

Cyclohexane iron powder, and observed the conversion rate of 1 1%.

There is 95% selective household oil [15]. But,

Looking for one-step production of adipic acid

Cyclohexane produces the most nitrogen oxides.

Problems to be solved urgently in green chemistry.

Thomas has some interesting works.

Colleagues are using molecular sieve catalysts.

Direct oxidation of cyclohexane with active site separation

Gas phase synthesis of adipic acid (solvent-free) [16, 17].

In similar research, modern and so on. ask

Selective MnAPO-5 catalyst

Oxidation of cyclohexane [18].