Non-mercury catalytic acetylene hydrochlorination over a NH₄F–urea-modified Pd/HY catalyst for vinyl chloride monomer production

Abstract

The modification of NH4F and urea significantly enhances the stability of a Pd/HY catalyst for acetylene hydrochlorination.

Adsorption Behavior and Electron Structure Engineering of Pd-Based Catalysts for Acetylene Hydrochlorination

“…Wang et al introduced K and NH 4 F promoters in Pd/HY catalyst. The presence of K and NH 4 F promoters exhibit a good effect on the acidity on the surface of catalyst and effectively inhibit the run off of Pd component [38][39][40][41][42][43]. Hu et al reported an (NPs)/surfactant ionic liquids system and constructed an effective redox cycle in catalytic system [61].…”

“…Recent studies have shown that Pd supported catalysts could be an efficient, low-cost, mercury-free alternative for acetylene hydrochlorination [29,[36][37][38][39][40][41][42][43]. However, the inherent volatilization of Pd component limits the use of Pd-based catalysts for producing VCM [36][37][38][39][40][41][42][43]. We have previously reported a supported-ionic-liquid-phase (SILP) Pd catalysts (Pd-IL/AC) for the acetylene hydrochlorination [29].…”

Acetylene hydrochlorination over boron-doped Pd/HY zeolite catalysts

“…Since Hutchings et al suggested that the activities of metal catalysts were associated with the standard electrode potentials of the related metal ions, 3 numerous studies have been carried out to develop non-mercury catalysts for efficient and sustainable hydrochlorination of acetylene in recent years, such as Au, [4][5][6][7][8][9][10][11] Pd, [12][13][14][15][16][17][18][19] Pt, 20 Ru, 21 Bi, 22 Cu, 23,24 etc. Based on the detailed study by Hutchings' team, 3 metal chloride/activated carbon catalysts (including Pd 2+ , Hg 2+ , Cu 2+ , Cu + , Ag + ) had superior catalytic activity and the order of their activities was Pd 2+ > Hg 2+ > Cu 2+ > Cu + > Ag + .…”

“…Therefore, palladium-based catalysts were reported to be active for acetylene hydrochlorination. [12][13][14][15][16][17][18][19] Wang et al prepared Pd-based/C catalysts via impregnation method and suggested that the Pd loss and the carbon deposition were main reasons for the catalyst deactivation, and the adding of K and La could improve the stability and regeneration of Pd/C catalysts. 18 Mitchenko et al reported that Pd(II) chloro complexes were the active sites of catalysts 19 and the (NH 4 ) 2 PdCl 4 complex could stabilize the Pd species resulted in improving the catalytic performance over carbon-based materials.…”

“…13 In our previous study, zeolites as new supports were prepared Pd/HY catalysts applied for acetylene hydrochlorination and the catalysts stabilities could be enhanced aer modication with NH 4 F or polyaniline. [14][15][16][17] While the carbon deposition and the active component reduction is the major obstacle to improve activity and stability of catalysts. It reported that heteroatom doping of support materials was effective for the improvement of the catalytic performance of metal catalysts 25 and few reports were studied on the B-doped zeolite-based catalysts for acetylene hydrochlorination at present.…”