CN85102710A - Platinum, Pd/TiO 2 deoxygenationcatalyst - Google Patents

Abstract

Platinum, palladium/titanium oxide catalyst are to be used for the catalyst that general hydrogen, nitrogen deoxidation are produced ultra-pure hydrogen, nitrogen.Feature of the present invention is to adopt N-type semiconductor titanium dioxide to make the carrier of catalyst, its bullion content A: platinum: 0.1～5.0% or B: platinum, palladium 0.1～5.0% (weight ratio).The former is applicable to that more general nitrogen purifies, and the latter is usually used in general hydrogen purification.Both air speeds are 10000～30000 hours ^-1, the residual oxygen content of finished product gas is at 20ppb～0.2ppm.Compare with known dehydrogenation catalyst, it is good that the present invention has catalytic activity, and the deoxidation degree of depth is dark, and the unit interval treating capacity is big, need not characteristics such as activation and regeneration.

Description

Platinum, Pd/TiO 2 deoxygenationcatalyst

Platinum of the present invention, palladium/titanium oxide are the catalyst that ultra-pure hydrogen or the quantitative deoxidization by adding hydrogen of general nitrogen are produced in general hydrogen deoxidation.It can be used for electronics industry, semi-conducting material and device production, the ultra-pure hydrogen that industry such as modern chemical industry, oil chemistry, metallurgy, instrument, aerospace and atomic energy is required or the preparation and the production process of nitrogen.

The principle of catalyst deoxygenation is to make in the impurity oxygen that is blended in the raw hydrogen or the general nitrogen quantitatively hydrogenation and impurity oxygen water generation reaction vapour (H under the effect of catalyst ₂O) remove.

Catalyst with the general hydrogen of catalytic conversion method for purifying has palladium/aluminium oxide (referring to Nissan Girdler Catalyst CO-LTD.Inspection Report On HI-P Catalyst(P.O.No 738288) 1980 at present); Palladium/molecular sieve (compiling " purification for gas " 21,1983, National Defense Industry Press) referring to Wu Yanmin; Palladium/carbon fiber (referring to Yang Xueren etc., catalysis journal 1(2) 81,1980) with aluminium oxide or silica is carrier, and noble metal adds catalyst such as iron, cobalt, nickel, rare earth oxide (referring to nineteen eighty-three Japan Patent J58026004, J58174239).The unit interval treating capacity of above-mentioned catalyst is calculated as 10000～20000 hours by sky is fast ^-1, the residual oxygen content that purifies back finished product gas is at 0.5～10ppm, and generally all needs activation and regeneration.

General nitrogen purifies the general oxide absorption process of appraising at the current rate that adopts of the method that removes impurity oxygen, and carbon burning consumes method and hydrogenation catalyst conversion method.Absorption process deoxidier commonly used has manganese oxide (MnOx), silver oxide (Ag ₂O), cupric oxide (CuOx) (is compiled " purification for gas " 23 referring to Wu Yanmin, 1983, National Defense Industry Press), the material that carbon burning consumes has the deoxidation amount of the above two kinds of deoxidiers of palladium-carbon and charcoal limited, the former is general, and every gram deoxidier removes oxygen 5-15 milliliter, though but 1500 milliliters of every gram deoxygenations of the latter just lost efficacy in case belong to the consumption-type emptied of material, and use down at higher temperature 320-900 ℃, and produce new impurity CO ₂And CO.

The objective of the invention is to prepare the high catalyst of a kind of activity, improving the unit interval treating capacity of general hydrogen deoxidation or the quantitative hydrogenation and removing oxygen of general nitrogen, improve the deoxidation degree of depth and in use exempt the activation and the regeneration of catalyst.For this reason, the present invention adopts N-type semiconductor titanium dioxide to make carrier, noble metal platinum or platinum, the two components of palladium are made the activity of such catalysts composition, and consider factors such as interaction between the metal-semiconductor, developed air speed big (10000～30000 hours with methods such as solution impregnation, electronation, high temperature hydrogen treatment ^-1), the catalytic deoxidation degree of depth is dark, and (remaining oxygen 20ppb～0.2ppm) need not the general hydrogen deoxygenation that activates and regenerate, the quantitative hydrogenation deoxidation catalyst of general nitrogen.The bullion content A of this catalyst: platinum 0.1～5.0% or B: platinum, palladium 0.1～5.0%(weight ratio), latter's platinum, palladium ratio are 1: 1.

This Preparation of catalysts step is: dipping → washing → drying → moulding → high temperature hydrogen treatment.Be that titania powder (anatase) is suspended in chloroplatinic acid or chloroplatinic acid and the palladium bichloride mixed aqueous solution and floods, hydrazine hydrate reduction, deionized water washing, 80-120 ℃ of drying, compression molding, hydrogen is handled in the tube furnace, 500～700 ℃ of temperature ranges, the electrical conductivity of finished catalyst are 10 ^-4～10 ^-1L/ Ω cm, specific area 8-12 rice ²/ gram, bulk density 1.1～1.5 grams per milliliters, 1～3 hour hydrogen processing time.

Example 1:0.2%(Pt+Pd)/TiO ₂Preparation

In the porcelain bucket of 5 liter capacity, inject 3500 ml deionized water, add 18 milliliters of chloroplatinic acid aqueous solution (0.1MH ₂PtCl ₆6H ₂O) and 42 milliliters of palladium chloride aqueous solutions, the back that stirs adds 200 gram titania powders, soaks to stir to add 120 milliliters of (50%N of hydrazine hydrate after 12 hours ₂H ₄H ₂O), continue to stir 3 hours, spend deionised water, until no Cl ^-, placing 80～120 ℃ of dryings in the baking oven, crushing screening is with tablet press machine moulding 3 * 3mm garden cylindrical particle.Place 500 ℃ of H in the tube furnace again ₂Handled 2 hours under the atmosphere, naturally cooling.

The present invention is used for general hydrogen and removes impurity oxygen, and service condition is:

Normal pressure, normal temperature; 100 kilograms per centimeter ²90～100 ℃ of (hydrogen pressure), reaction temperatures; 110 ℃ of 170 kilograms per centimeter, reaction temperatures

Air speed scope 10000～30000 hours ^-1; The beds ratio of height to diameter is not less than 10; Need not activation and regeneration.Use the finished product gas residual impurity oxygen content 20ppb～0.2ppm after the present invention purifies by above-mentioned condition.

Example 2: in purification pipe, load catalyst (the beds ratio of height to diameter is greater than 10) 0.2%(Pt+Pd)/TiO ₂10000 hours ^-1Air speed, normal pressure, it is 20ppb(TE-150 look, spectrometer analysis that normal temperature, general hydrogen (impurity oxygen 500ppm) purify finished product gas remaining oxygen).

Example 3:0.2%(Pt+Pd)/TiO ₂Catalyst turns round more than a year 170 kilograms per centimeter in the general hydrogen purification flow process of ester through hydrogenation system alcohol process ²Under (hydrogen pressure) 110 ℃ of temperature, treating capacity is 2 meters ³/ hour, its catalytic deoxidation performance is stable always, and remaining oxygen is the test of 0.2ppm(DH-3 trace oxygen analyzer), the catalytic deoxidation property retention is constant after more than 10 times stop (pressurize, cooling) starts.

Example 4:0.2%(Pt+Pd)/TiO ₂Catalyst turns round in the general hydrogen purification flow process of semiconductor devices production process, normal pressure～100 kilograms per centimeter ², under ℃ condition of normal temperature～90, treating capacity is 45 meters ³/ hour, the finished product gas remaining oxygen after the purification is measured for the 0.2ppm(DH-3 trace oxygen analyzer).

The present invention is used for the quantitative deoxidization by adding hydrogen process of general nitrogen

Example 5:0.5%Pt/TiO ₂Catalyst is at normal pressure, 10000 hours ^-1Under the air speed, in 25 ℃ of different temperatures, 0 ℃ ,-78 ℃ of general nitrogen, quantitative hydrogenation deoxidation, its deoxidation degree of depth all reaches the ppb level.See Table 1.

The quantitative hydrogenation deoxidation performance of general nitrogen under table 1 different temperatures

Impurity oxygen content (ppm) hydrogen content (ppm) reaction temperature (℃) residual oxygen content (PPb*)

5000 10000 25 20

5000 10000 0 20

5000 10000 -78 50

^*TE-150 look-spectrometer analysis

Example 6: different samples of the present invention are the quantitative hydrogenation deoxidation long-term operation of general nitrogen stable performance under normal temperature, normal pressure, sees Table 2.

The long-time behavior in service of the quantitative hydrogenation deoxidation of the general nitrogen of the different samples of table 2

Air speed O ₂Content H ₂Content duration of runs

The residual O of catalyst ₂Amount

(hour ^-1) (ppm) (ppm) (hour)

15%Pt/

10000 5000 10000 500 20ppb ^＊

TiO ₂

0.2%Pt/

10000 5000 10000 514 0.2ppm ^＊＊

TiO ₂

^*TE-150 look-spectrometer analysis

^*The DH-3 trace oxygen analyzer is analyzed

Compare with known dehydrogenation catalyst, it is good that the present invention has catalytic activity, and the deoxidation degree of depth is dark, and the unit interval treating capacity is big, and need not give activation before use, does not need characteristics such as regeneration in the use.

Claims (6)

1, is used for general hydrogen, the platiniferous of nitrogen deoxidation, palladium catalyst, the invention is characterized in that the carrier of catalyst adopts N-type semiconductor material titanium dioxide.Its bullion content A: platinum: 0.1～5.0% or B: platinum, palladium 0.1～5.0% (weight ratio).

2, according to claim 1 described catalyst B, platinum, palladium ratio are 1: 1.

3, according to claim 1 described titanium dioxide, preferably select anatase for use.

4, according to claim 1 described Preparation of catalysts method be:

(1) titania powder is suspended in A: chloroplatinic acid or B: flood in chloroplatinic acid and the palladium chloride aqueous solution, add hydrazine hydrate reduction (N ₂H ₄H ₂O 50%), spend deionised water, in 80～120 ℃ of dryings, moulding.

(2) catalyst after the moulding was handled 1～3 hour under 500～700 ℃ of nitrogen atmosphere.

5, according to claim 1 described catalyst, its electrical conductivity is 10 ^-4～10 ^-1L/ Ω cm.

6, be more suitable for the quantitative hydrogenation deoxidation of general nitrogen according to claim 1 described catalyst A, catalyst B is more suitable for general hydrogen deoxidation.