Sulfur carbon ball loaded precious metal catalyst and preparation method and application thereof

Abstract

The invention discloses a sulfur carbon ball loaded precious metal catalyst and a preparation method and application thereof. The catalyst is prepared from a sulfur carbon ball and an active componentloaded on the surface of the sulfur carbon ball; elemental sulphur of the sulfur carbon ball exists on a skeleton and the surface of the sulfur carbon ball in a C-S bond form, wherein the mass ratioof the elemental sulfur to elemental carbon is 0.05-20%; the active component is platinum family metal particles, and the particle size of the platinum family metal particles is 4-10 nm; and the sulfur carbon ball loaded precious metal catalyst is spherical, and the diameter of the sulfur carbon ball loaded precious metal catalyst is 100-1000 nm. The invention provides application of the catalystto a C=N bond selective catalytic hydrogenation reduction reaction. The sulfur carbon ball is synthetized through 4,4'-thiobis-thiophenol self-polymerization in-situ sulfur doping, thus the elementalsulphur exists on the skeleton and the surface of the sulfur carbon ball in the C-S bond form, and the metal dispersity and the outer-layer electron distribution characteristic of the modulated metalparticles can be effectively improved; and the catalyst is applied to the C=N bond selective catalytic hydrogenation reaction, and represents the advantages of high conversion rate, catalytic activity, stability and reaction rate.

Description

(1) Technical field [0001] The invention relates to a sulfur-carbon sphere-supported noble metal catalyst and its preparation method and application, in particular to the application of the catalyst in C=N bond selective hydrogenation reaction. (2) Technical background [0002] Platinum group metals have shown excellent catalytic performance in many chemical reactions, such as carbonyl addition reaction, acid chloride addition reaction, olefin oxidation reaction, and C-C synthesis reaction in homogeneous catalytic reactions. The heterogeneous catalysts mainly include petroleum reforming Pt -Re / Al 2 o 3 Catalyst, automobile exhaust purification Pt-Rh / Al 2 o 3 Catalyst, Pd / C catalyst for hydrogenation of terephthalic acid purification, Pd / C catalyst for catalytic hydrogenation of chloronitrobenzene. However, there are still several problems to be solved in the selective hydrogenation reduction reaction. [0003] 1) Efficient utilization of metals. Platinum group metals e...

AI Technical Summary

Problems solved by technology

However, there are inevitably differences in the properties of activated carbon produced by different manufacturers, different materials and different batches, resulting in the instability of the preparation process of carbon-supported noble metal catalysts.

[0004] 2) Selectivity needs to be improved

For the surface modification of the support, the method of doping a large number of basic groups such as S is often to combine the support and sulfur-containing compounds such as H 2 S, elemental S, etc. are roasted at high temperature. The experimental steps of this method are complicated, and it is not easy to control the formation of specific surface sulfur-containing groups; for the modification of metal particles, most of them use supported platinum group metal catalysts such as Pd / C and sulfur-containing compounds. Such as phenylene sulfide, etc. are mixed, and the sulfur-containing complex is adsorbed on the metal active site through chemical adsorption force

The experimental steps of this kind of method are simple, and the adsorption force between the sulfur-containing complex and the active site is not strong, which leads to the unsatisfactory effect of doping sulfur, and it is often necessary to continuously add to the reactor

Therefore, this type of method is likely to cause a series of new problems such as separation and pollution to subsequent processes.

Images