CN109746006A - Gas phase dehydrofluorination synthesizes 1,3,3,3- tetrafluoropropene with long-life, environmental protection catalyst - Google Patents

Abstract

The present invention discloses a kind of gas phase catalysis 1,1,1,3,3- pentafluoropropane dehydrofluorination synthesis 1,3,3,3- tetrafluoropropene with long-life, environmental protection catalyst.It is a series of a large amount of the problems such as causing serious pollutions, health using heavy metal chromium and short problem of existing Dehydrofluorination catalyst service life in order to solve traditional chromium/catalytic component based on vanadium there are environmental problem.Catalyst group disclosed by the invention becomes M/MgF₂, wherein matrix MgF₂To be greater than 120m with Rutile Type and nanometer spherical structure, specific surface area²/ g, the superior high stability MgF of anti-sintering property in 500 DEG C₂, active component M is selected from Co³⁺、Ni²⁺、Fe³⁺、Zn²⁺、La³⁺、Al³⁺、Ga³⁺、Mn⁴⁺、Cu²⁺One or more of.Catalyst preparation is added dropwise fluorination reagent at 150~240 DEG C and obtains catalyst xerogel the following steps are included: the polyhydric alcohol solutions of (1) preparation source containing magnesium and doped metal ion；(2) xerogel is roasted at 300~500 DEG C, finally long-life, environment-friendly and high-performance catalyst is made in fluorination treatment at 150~400 DEG C.

Description

Gas phase dehydrofluorination synthesizes 1,3,3,3- tetrafluoropropene with long-life, environmental protection catalyst

Technical field

The present invention relates to a kind of catalyst, and in particular to a kind of 1,1,1,3,3- pentafluoropropane dehydrofluorination of gas phase catalysis conjunction At 1,3,3,3- tetrafluoropropene with long-life, environmental protection catalyst.

Background technique

1,1,1,3- tetrafluoropropene, abbreviation HFO-1234ze, molecular formula CF₃CH=CHF, nontoxic, non-ignitable, ODP zero, GWP is about 6, and the atmosphere residence time is short, and stable chemical performance, refrigeration performance is good, and it is single that research finds that HFO-1234ze can be done The refrigerant and foaming agent of working medium substitute HFC-134a.

It so far, is raw material through gas with 1,1,1,3,3- pentafluoropropane in known numerous HFO-1234ze synthetic methods The synthesis of phase dehydrofluorination has the characteristics that easy to operate, space-time yield is high, is easy to amplify, most by the concern of industry, center Heart technology is corresponding Dehydrofluorination catalyst.Chinese patent CN107042104A discloses a kind of Cr₂O₃-NiO-MgF₂Load Type catalyst realizes that 1,1,1,3,3- pentafluoropropane gas phase dehydrofluorination synthesizes HFO-1234ze.Chinese patent CN107715897A Disclose a kind of V₂O₅/AlF₃C catalyst realizes above-mentioned gas phase dehydrofluorination reaction.Chinese patent CN101265155B is disclosed Using fluorination Cr₂O₃、AlF₃, 10%MgF₂- 90%AlF₃In realize gas phase dehydrofluorination in the presence of one or more catalyst Synthesize HFO-1234ze.Chinese patent CN105431100B, which is disclosed, uses a kind of Al₂O₃Loaded catalyst realizes gas phase defluorinate It is combined to HFO-1234ze, active component is selected from the inorganic salts of K, Zn and Mg.

The anti-applications catalyst majority of the gas phase dehydrofluorination of above-mentioned report is using chromium, vanadium as core component, however chromium, vanadium conduct Heavy metal element, a large amount of discharges can cause ecological environment seriously to pollute；Especially Cr VI is a kind of extremely toxic substance to animal, people Class health, which is constituted, greatly to threaten.In addition, all being deposited although above-mentioned catalyst shows higher reactivity in use process In the problem of stability difference, it cannot achieve long period, the reaction of high stable catalytic dehydrofluorination, industrial application mark be still not achieved It is quasi-.Based on this, to cope with increasingly serious Environmental Protection Situation and industrial application, there is an urgent need to design, prepare long-life, environment protection catalytic Agent is for the synthesis HFO-1234ze reaction of gas phase 1,1,1,3,3- pentafluoropropane dehydrofluorination.

Summary of the invention

In view of the defects existing in the prior art with deficiency, the object of the present invention is to provide one kind without chromium/vanadium, environment friend The anti-applications catalyst of gas phase dehydrofluorination good, the service life is long.This catalyst of the invention has without heavy metal, green ring The good feature of guarantor, large specific surface area, nanometer spherical structure, the anti-caking power of high temperature, to obtain high activity, high catalytic stability Gas phase catalysis dehydrofluorination performance.

Traditional chromium-based fluorination catalyst large specific surface area, generally in 80~150m²/ g, high-specific surface area create a large amount of anti- Active sites are answered, it is thus achieved that the Efficient Conversion of gas phase fluorination.In consideration of it, by design, constructing in high temperature containing fluorine atmosphere The high-specific surface area MgF that can be equally stabilized down₂, and then by adulterate other metal ions realize its surface acid center and The regulation of texturizing properties can be obtained equally and have active sites needed for catalytic vapor phase fluorination reacts.In addition, passing through control MgF₂Ruler Very little can be greatly improved mass-transfer efficiency in nanoscale and spherical structure, so that macrodynamics reaction row in heterogeneous catalysis process To be improved and carbon deposition rate being effectively reduced.The foundation of above-mentioned multiple unique texture, structure is so that environmental type high-performance The preparation of vapor phase dehydrofluorination catalysts is achieved.

In order to realize above-mentioned technical assignment, the present invention is realised by adopting the following technical scheme:

A kind of gas phase dehydrofluorination synthesis 1,3,3,3- tetrafluoropropenes long-life, environmental protection catalyst, the catalyst group As M/MgF₂, wherein matrix MgF₂To be greater than 120m with Rutile Type and nanometer spherical structure, specific surface area²/g、500℃ The interior superior high stability MgF of anti-sintering property₂, active component M is selected from Co³⁺、Ni²⁺、Fe³⁺、Zn²⁺、La³⁺、Al³⁺、Ga³⁺、Mn^{4 +}、Cu²⁺One or more of, M mass accounts for the 5%~20% of catalyst gross mass；

The method for preparing catalyst is as follows:

(1) to containing Mg at 150~240 DEG C²⁺And fluorination reagent is added dropwise in the polyhydric alcohol solutions of M, continue after being added dropwise 6~12h is stirred, M/MgF is obtained₂Xerogel；

Magnesium salts used is selected from one of magnesium nitrate, magnesium chloride, magnesium sulfate, magnesium methoxide, magnesium ethylate, magnesium acetate；

M used is selected from one or more of nitrate, chloride, sulfate；

Polyalcohol used is selected from one or more of ethylene glycol, propylene glycol, glycerine, tirethylene glycol；

Fluorination reagent used is selected from one of aqueous solution, alcoholic solution, ethereal solution of hydrogen fluoride；

Mg²⁺Molar ratio with hydrogen fluoride is 1:3~12；

(2) made xerogel in (1) is heat-treated at 300~500 DEG C, then to heat at 150~400 DEG C Xerogel carries out fluorination treatment and M/MgF is made after processing₂Catalyst；

Heat-treating atmosphere is carried out selected from one of air, nitrogen, hydrogen atmosphere；

Fluorine reagent used in fluorination treatment is in hydrogen fluoride, dicholorodifluoromethane, F-22, monochlorotrifluoromethane One kind；

Gas phase dehydrofluorination described further synthesizes 1,3,3,3- tetrafluoropropene long-life, environmental protection catalyst, features It is that M is Fe³⁺、Al³⁺Combination, Fe³⁺With Al³⁺Molar ratio be 1:1~0.2.

Gas phase dehydrofluorination described further synthesizes 1,3,3,3- tetrafluoropropene with long-life, the preparation side of environmental protection catalyst Method, the concentration of the fluorination reagent are 20wt.%~70wt.%.

Long-life described further, environmental protection catalyst, the catalyst are used for 1,1,1,3,3- pentafluoropropane dehydrofluorination Synthesize the reaction of 1,3,3,3- tetrafluoropropene.

Beneficial effects of the present invention: compared with prior art, the present invention having following beneficial technical effect:

1. the present invention provides a kind of specific surfaces without heavy metal, environmental-friendly compared with traditional chromium/catalytic component based on vanadium The good MgF of long-pending big, nanometer spherical structure, the anti-caking power of high temperature₂Base Dehydrofluorination catalyst and preparation method thereof；2. the present invention The preparation method of offer can be easily achieved the modulation to made catalyst texture, structure and surface acidity, and specific surface can be made Product is greater than 120m²/ g, the superior fluorination magnesium-base catalyst of anti-sintering property in 500 DEG C；3. the present invention is to magnesium source used without special It is required that applicability is wide, it is at low cost；4. nanometer spherical prepared by the present invention is fluorinated magnesium-base catalyst, facilitates material and be catalyzed Agent surface adsorption desorption improves mass transfer, and then improves reaction efficiency, inhibits carbon distribution, to obtain high catalytic stability, uses Service life is much higher than existing Dehydrofluorination catalyst.

Detailed description of the invention

Fig. 1 is M/MgF₂The catalytic dehydrofluorination of catalyst reacts life test result

Specific embodiment

Specific embodiments of the present invention are given below, but do not limit the scope of the invention.

Catalyst performance evaluation is as follows: measuring 30mL catalyst and is transferred in fixed-bed tube reactor, is warming up to 350 DEG C simultaneously 1,1,1,3,3- pentafluoropropane is passed through after dry 2h, time of contact is 18 seconds, and product is through water, alkali cleaning absorption fluorination after running 12h The laggard gas chromatograph of hydrogen, hydrogen chloride is analyzed, and the conversion of 1,1,1,3,3- pentafluoropropane is calculated using area normalization method Rate and target product HFO-1234ze selectivity.

Embodiment 1: preparation M/MgF₂Catalyst

1.0M magnesium source and 0.01~0.1M modified metal ion are dissolved in 50mL polyol solvent, stirred at 150~240 DEG C Mix it is lower fluorination reagent is added drop-wise in above-mentioned solution, time for adding 15min is stirred for 6~12h after being added dropwise, obtains M/ MgF₂Xerogel；Then 5h or more is roasted at air atmosphere or 300~500 DEG C of nitrogen atmosphere, finally in 150~400 DEG C of program liters Temperature carries out fluorination treatment to material after roasting and obtains catalyst, and fluorine reagent selects gaseous hydrogen fluoride, dicholorodifluoromethane, a chlorine two Any one in fluoromethane, monochlorotrifluoromethane.Under different magnesium sources, polyol solvent, coagulant, fluorination reagent, maturing temperature Magnesium fluoride texture property obtained is shown in Table 1.

The physico-chemical property result of the fluorination magnesium-base catalyst of 1 embodiment 1 of table

Embodiment 2

M/MgF is prepared using same procedure in embodiment 1₂Catalyst applies it to 1,1,1,3,3- five fluorine third of gas phase Alkane dehydrofluorination synthesizes in HFO-1234ze reaction, and after running 12h, reaction result is as follows:

The reaction evaluating result of the fluorination magnesium-base catalyst of 2 embodiment 2 of table

Embodiment 3

M/MgF is prepared using same procedure in embodiment 1₂Catalyst applies it to 1,1,1,3,3- five fluorine third of gas phase Alkane dehydrofluorination synthesizes in HFO-1234ze reaction, and after running 12h, reaction result is as follows:

The reaction evaluating result of the fluorination magnesium-base catalyst of 3 embodiment 3 of table

Claims (4)

1. a kind of gas phase dehydrofluorination synthesizes 1,3,3,3- tetrafluoropropenes with long-life, environmental protection catalyst, it is characterised in that described Catalyst group becomes M/MgF₂, wherein matrix MgF₂To be greater than 120m with Rutile Type and nanometer spherical structure, specific surface area²/ G, the superior high stability MgF of anti-sintering property in 500 DEG C₂, active component M is selected from Co³⁺、Ni²⁺、Fe³⁺、Zn²⁺、La³⁺、Al³⁺、 Ga³⁺、Mn⁴⁺、Cu²⁺One or more of, M mass accounts for the 5%~20% of catalyst gross mass；

The method for preparing catalyst is as follows:

(1) to containing Mg at 150~240 DEG C²⁺And fluorination reagent is added dropwise in the polyhydric alcohol solutions of M, continue stirring 6 after being added dropwise ~12h obtains M/MgF₂Xerogel；

Magnesium salts used is selected from one of magnesium nitrate, magnesium chloride, magnesium sulfate, magnesium methoxide, magnesium ethylate, magnesium acetate；

M used is selected from one or more of nitrate, chloride, sulfate；

Polyalcohol used is selected from one or more of ethylene glycol, propylene glycol, glycerine, tirethylene glycol；

Fluorination reagent used is selected from one of aqueous solution, alcoholic solution, ethereal solution of hydrogen fluoride；

Mg²⁺Molar ratio with hydrogen fluoride is 1:3~12；

(2) made xerogel in (1) is heat-treated at 300~500 DEG C, then to heat treatment at 150~400 DEG C Xerogel carries out fluorination treatment and M/MgF is made afterwards₂Catalyst；

Heat-treating atmosphere is carried out selected from one of air, nitrogen, hydrogen atmosphere；

Fluorine reagent used in fluorination treatment in hydrogen fluoride, dicholorodifluoromethane, F-22, monochlorotrifluoromethane one Kind.

2. gas phase dehydrofluorination synthesizes 1,3,3,3- tetrafluoropropenes with long-life, environmental protection catalyst according to claim 1, It is characterized in that M is Fe³⁺、Al³⁺Combination, Fe³⁺With Al³⁺Molar ratio be 1:1~0.2.

3. gas phase dehydrofluorination synthesizes 1,3,3,3- tetrafluoropropenes with long-life, environmental protection catalyst according to claim 1, The concentration for being characterized in that the fluorination reagent is 20wt.%~70wt.%.

4. gas phase dehydrofluorination synthesizes 1,3,3,3- tetrafluoropropenes long-life, environmental protection catalyst, institute according to claim 1 State gas phase catalysis dehydrofluorination synthesis 1,3,3,3- tetrafluoropropene reaction of the catalyst for 1,1,1,3,3- pentafluoropropane.