The present invention provides the use of a metal-doped hydroxyapatite catalyst for highly selective conversion of an alcohol to an aldehyde at low temperatures. More specifically, the invention provides the use of a silver-doped hydroxyapatite catalyst for the highly selective oxidative dehydrogenation of ethanol to acetaldehyde. The present invention also provides the method for converting ethanol to acetaldehyde using a silver-doped hydroxyapatite catalyst.

A process for preparing a catalyst by selecting an active catalyst and contacting the active catalyst with one or more fluids containing an organic solvent or mixture of organic solvents. In one embodiment, each organic solvent has a dielectric constant within a range of about 5 to about 55 when measured at a temperature of 20 C. to 25 C. The catalyst thus prepared may be used in a process for preparing maleic anhydride.

A process for preparing a catalyst by selecting an active catalyst and contacting the active catalyst with one or more fluids containing an organic solvent or mixture of organic solvents. In one embodiment, each organic solvent has a dielectric constant within a range of about 5 to about 55 when measured at a temperature of 20 C. to 25 C. The catalyst thus prepared may be used in a process for preparing maleic anhydride.

The invention relates to a catalyst composition comprising a mixed oxide of vanadium, titanium, and phosphorus. The titanium component is derived from a water-soluble, redox-active organo-titanium compound. The catalyst composition is highly effective at facilitating the vapor-phase condensation of formaldehyde with acetic acid to generate acrylic acid, particularly using an industrially relevant aqueous liquid feed. Additionally, the catalyst composition is catalytically active towards the formation of acrylic acid from methylene diacetate and methacrylic acid from methylene dipropionate; both reactions are carried out with high space time yields.

The invention relates to a catalyst composition comprising a mixed oxide of vanadium, titanium, and phosphorus. The titanium component is derived from a water-soluble, redox-active organo-titanium compound. The catalyst composition is highly effective at facilitating the vapor-phase condensation of formaldehyde with acetic acid to generate acrylic acid, particularly using an industrially relevant aqueous liquid feed. Additionally, the catalyst composition is catalytically active towards the formation of acrylic acid from methylene diacetate and methacrylic acid from methylene dipropionate; both reactions are carried out with high space time yields.

A catalytic converter arrangement for producing phthalic anhydride by means of a gas phase oxidation of aromatic hydrocarbons, comprising a reactor with a gas inlet side for a reactant gas, a gas outlet side for a product gas, a first catalytic converter layer made of catalytic converter elements, and at least one second catalytic converter layer made of catalytic converter elements. The first catalytic converter layer is arranged on the gas inlet side, and the second catalytic converter layer is arranged downstream of the first catalytic converter layer in the gas flow direction. The catalytic converter elements have an outer layer of an active compound. The invention is characterized in that the active compound content in the first catalytic converter layer and/or in the second catalytic converter layer is below 7 wt. %, based on the total weight of the catalytic converter elements, and the ratio of the total surface of the active compound to the volume of the catalytic converter layer is preferably 10000 cm1 to 20000 cm1, in each catalytic converter layer.

A promoted VPO catalyst for the oxidation of n-butane to maleic anhydride wherein the catalyst comprises the mixed oxides of vanadium and phosphorus, niobium and at least one of antimony and bismuth, wherein the catalyst may be produced in a process comprising impregnating a VPO catalyst with a metal source compound of niobium and a metal source compound of at least one of antimony and bismuth, to form a metal impregnated VPO catalyst, and then drying the metal impregnated VPO catalyst to form the promoted VPO catalyst.

A promoted VPO catalyst for the oxidation of n-butane to maleic anhydride wherein the catalyst comprises the mixed oxides of vanadium and phosphorus, niobium and at least one of antimony and bismuth, wherein the catalyst may be produced in a process comprising impregnating a VPO catalyst with a metal source compound of niobium and a metal source compound of at least one of antimony and bismuth, to form a metal impregnated VPO catalyst, and then drying the metal impregnated VPO catalyst to form the promoted VPO catalyst.

The present invention relates to a process for preparing acrylic acid from formaldehyde and acetic acid, comprising reacting formaldehyde and acetic acid via an aldol condensation in a reaction unit comprising n reaction zones arranged in series, each comprising an aldol condensation catalyst, where n is at least 2, and wherein at least one stream leaving a reaction zone, before being fed into the reaction zone immediately downstream, is mixed with a stream comprising formaldehyde and optionally comprising acetic acid. The present invention further relates to an apparatus for preparing acrylic acid from formaldehyde and acetic acid and to the use of this apparatus.

The present invention relates to a catalyst system for oxidation of o-xylene and/or naphthalene to phthalic anhydride (PA), comprising a plurality of catalyst zones arranged in succession in the reaction tube, which has been produced using antimony trioxide consisting predominantly of the senarmontite modification of which all primary crystallites have a size of less than 200 nm. The present invention further relates to a process for gas phase oxidation, in which a gas stream comprising at least one hydrocarbon and molecular oxygen is passed through a catalyst system which comprises a plurality of catalyst zones arranged in succession in the reaction tube and which has been produced using an antimony trioxide consisting predominantly of the senarmontite modification with a median primary crystallite size of less than 200 nm.