Abstract: A process for the disproportionation of toluene over a nickel-modified mordenite catalyst which has been pretreated with mild sulfiding procedure. The sulfur dose is employed in a minor amount relative to the nickel content of the catalyst. The modified mordenite catalyst is contacted with a sulfur-containing compound such as hydrogen sulfide or dimethyldisulfide (DMDS) under pretreatment conditions involving a temperature of at least 100° C. The sulfur-containing compound is employed in a relatively small amount to passivate only a minor portion of the active nickel sites. A toluene-containing feedstock is brought into contact with the pretreated catalyst under conditions effective for the disproportionation of toluene and a disproportionation product is removed from contact with the catalyst. The mordenite catalyst contains nickel in an amount within the range of 0.1-2 wt. %. The catalyst may contain another metal such as palladium or platinum, or a lanthanide series metal such as lanthanum or cerium.

Abstract: A process for the disproportionation of toluene over a nickel-modified mordenite catalyst which has been pretreated with mild sulfiding procedure. The sulfur dose is employed in a minor amount relative to the nickel content of the catalyst. The modified mordenite catalyst is contacted with a sulfur-containing compound such as hydrogen sulfide or dimethyldisulfide (DMDS) under pretreatment conditions involving a temperature of at least 100° C. The sulfur-containing compound is employed in a relatively small amount to passivate only a minor portion of the active nickel sites. A toluene-containing feedstock is brought into contact with the pretreated catalyst under conditions effective for the disproportionation of toluene and a disproportionation product is removed from contact with the catalyst. The mordenite catalyst contains nickel in an amount within the range of 0.1-2 wt. %. The catalyst may contain another metal such as palladium or platinum, or a lanthanide series metal such as lanthanum or cerium.

Abstract: Nitrogen and optionally sulfur contamination can be removed from catalysts, such as spent and regenerated catalysts, by stripping them with a hydrogen-containing stream at high temperatures, such as between about 100 to about 600° C. Lower pressures such as a gauge pressure below about 10 MPa favors nitrogen removal, whereas relatively higher pressure, for instance from about 0.5 MPa to about 8 MPa encourages sulfur removal. The metal dispersion, increased after the hot hydrogen stripping of the spent catalyst.