The method for preparing fluorine-doped lamellar black TiO.sub.2 nanomaterials includes mixing a solution of tetra-n-butyl titanate, n-propanol and hydrofluoric acid together, and then stir the solutions for a period of time. The solution is transferred into an autoclave and reacts at a certain temperature for a period of time. The sample obtained by the reaction is washed and dried. Then, the sample is heated in a protective atmosphere for a period of time so as to produce the fluorine-doped lamellar black TiO.sub.2 nanomaterials. This fluorine-doped lamellar black TiO.sub.2 owns superior optical absorption and electron transport performances.

The invention concerns a process for preparing a chlorine comprising catalyst by (a) providing a Fischer-Tropsch catalyst comprising titania and at least 5 weight percent cobalt; (b) impregnating the catalyst with a solution comprising chloride ions; and (c) heating the impregnated catalyst at a temperature in the range of between 100 and 500 C. for at least 5 minutes up to 2 days. The prepared catalyst preferably comprises 0.13-3 weight percent of the element chlorine. The invention further relates to the prepared catalyst and its use.

The invention concerns a process for preparing a chlorine comprising catalyst by (a) providing a Fischer-Tropsch catalyst comprising titania and at least 5 weight percent cobalt; (b) impregnating the catalyst with a solution comprising chloride ions; and (c) heating the impregnated catalyst at a temperature in the range of between 100 and 500 C. for at least 5 minutes up to 2 days. The prepared catalyst preferably comprises 0.13-3 weight percent of the element chlorine. The invention further relates to the prepared catalyst and its use.

The invention relates to a method to start up a Fischer-Tropsch process. A catalyst with a latent activity is used. The catalyst comprises titania, cobalt, promoter, and chlorine. The catalyst comprises more than 0.7 and less than 4 weight percent of the element chlorine, calculated on the total weight of the catalyst.

The invention relates to a method to start up a Fischer-Tropsch process. A catalyst with a latent activity is used. The catalyst comprises titania, cobalt, promoter, and chlorine. The catalyst comprises more than 0.7 and less than 4 weight percent of the element chlorine, calculated on the total weight of the catalyst.

A method for synthesizing dimethyl carbonate from methanol and urea, in which a saline ureic medium is used that includes at least one inorganic salt selected from the group made up of zinc (Zn) (II) chloride, tin (Sn) chlorides and iron (Fe) (III) chloride, characterized in that: methanol, in the presence of a catalytic composition, is placed in contact with the saline ureic medium that is at least partially liquid at a temperature referred to as synthesis temperature, which is higher than 140 C., such that reaction vapors are produced; the reaction vapors are condensed, and a condensate of the reaction vapors is collected, including dimethyl carbonate; the method is carried out at atmospheric pressure. A method for enriching and purifying dimethyl carbonate is also described.

A method for synthesizing dimethyl carbonate from methanol and urea, in which a saline ureic medium is used that includes at least one inorganic salt selected from the group made up of zinc (Zn) (II) chloride, tin (Sn) chlorides and iron (Fe) (III) chloride, characterized in that: methanol, in the presence of a catalytic composition, is placed in contact with the saline ureic medium that is at least partially liquid at a temperature referred to as synthesis temperature, which is higher than 140 C., such that reaction vapors are produced; the reaction vapors are condensed, and a condensate of the reaction vapors is collected, including dimethyl carbonate; the method is carried out at atmospheric pressure. A method for enriching and purifying dimethyl carbonate is also described.

Methods for preparing a fluorided chromium catalyst can include a step of calcining a supported chromium catalyst at a peak calcining temperature to produce a calcined supported chromium catalyst, followed by contacting the calcined supported chromium catalyst at a peak fluoriding temperature with a vapor comprising a fluorine-containing compound to produce the fluorided chromium catalyst. The peak fluoriding temperature can be at least 50 C. less, and often from 200 C. to 500 C. less, than the peak calcining temperature. Polymers produced using the fluorided chromium catalyst can have a beneficial combination of higher melt index, narrower molecular weight distribution, and lower long chain branch content.

Provided are an exhaust gas purifying catalyst having high catalytic activity enabling combustion of PM at low temperatures and free from any risk of dispersal of metal elements arousing concern about environmental load, an exhaust gas purification device and filter having a high combustion efficiency of PM, and a method for producing the catalyst. An exhaust gas purifying catalyst contains: an oxide containing at least one element (A) selected from alkali metals and alkaline earth metals and at least one element (B) selected from Zr, Si, Al, and Ti; and a cesium salt.

The present invention concerns spheroidal alumina particles, catalysts comprising such particles as a support and a process for the production of spheroidal alumina particles, comprising the following steps: a) preparing a suspension comprising water, an acid and at least one boehmite powder for which the ratio of the crystallite dimensions in the [020] and [120] directions obtained using the Scherrer X-ray diffraction formula is in the range 0.7 to 1; b) adding a pore-forming agent, a surfactant and optionally water, or an emulsion comprising at least one pore-forming agent, a surfactant and water to the suspension of step a); c) mixing the suspension obtained in step b); d) shaping the spheroidal particles by the oil-drop method using the suspension obtained in step c); e) drying the particles obtained in step d); f) calcining the particles obtained in step e).