摘要:
The present invention relates to a process for gas-phase oxidation, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed through two or more catalyst zones. Furthermore, the present invention relates to a catalyst system for gas-phase reaction using a preliminary zone.
摘要:
A chemical mechanical polishing (CMP) composition comprising a specific heteropolyacid Abstract A chemical-mechanical polishing (CMP) composition comprising: (A) inorganic particles, organic particles, or a mixture thereof, (B) a heteropolyacid of the formula HaXbPsMOyVzOc wherein X=any cation other than H 8 0 and a>0 (formula I) or a salt thereof, and, (C) an aqueous medium.
摘要:
The present invention relates to a multilayer catalyst for preparing phthalic anhydride which has a plurality of catalyst layers arranged in succession in the reaction tube, with the individual catalyst layers having alkali metal contents which decrease in the flow direction. The present invention further relates to a process for the oxidation of naphthalene or o-xylene/naphthalene mixtures over such a multilayer catalyst and the use of such multilayer catalysts for the oxidation of naphthalene or o-xylene/naphthalene mixtures to phthalic anhydride.
摘要:
Mo-, Bi- and Fe-comprising multimetal oxide compositions of the general stoichiometry I, Mo12BiaCobFecKdSieOx (I), where a=0.5 to 1, b=7 to 8.5, c=1.5 to 3.0, d=0 to 0.15, e=0 to 2.5 and x=the stoichiometric coefficient of O2− which guarantees the electric neutrality of the multimetal oxide, and 12−b−1.5·c=A and 0.5≦A≦1.5, 0.2≦a/A≦1.3, and 2.5≦b/c≦9, and the use thereof.
摘要:
A chemical mechanical polishing (CMP) composition comprising a specific heteropolyacid Abstract A chemical-mechanical polishing (CMP) composition comprising: (A) inorganic particles, organic particles, or a mixture thereof, (B) a heteropolyacid of the formula HaXbPsMOyVzOc wherein X=any cation other than H 8 0 and a>0 (formula I) or a salt thereof, and, (C) an aqueous medium.
摘要:
The present invention relates to a process for gas-phase oxidation, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed through two or more catalyst zones. Furthermore, the present invention relates to a catalyst system for gas-phase reaction using a preliminary zone.
摘要:
Mo-, Bi- and Fe-comprising multimetal oxide compositions of the general stoichiometry I, Mo12BiaCobFecKdSieOx (I), where a=0.5 to 1, b=7 to 8.5, c=1.5 to 3.0, d=0 to 0.15, e=0 to 2.5 and x=the stoichiometric coefficient of O2− which guarantees the electric neutrality of the multimetal oxide, and 12−b−1.5·c=A and 0.5≦A≦1.5, 0.2≦a/A≦1.3, and 2.5≦b/c≦9, and the use thereof.
摘要:
The invention relates to a catalyst for the oxidation of SO2 to SO3. The catalyst contains an active substance which contains vanadium, alkali metal compounds and sulfate applied to a support. The support contains naturally occurring diatomaceous earth, wherein the support contains at least one relatively soft naturally occurring uncalcined diatomaceous earth which has a percentage reduction of at least 35% in its D50 value determined in a particle size determination according to the dry method in comparison with the wet method.
摘要:
A process for long-term operation of a heterogeneously catalyzed partial gas phase oxidation of propene to acrolein, in which the propene present in the reaction gas input mixture is partially oxidized as this gas mixture passes through the fixed catalyst bed which is accommodated in two spatially successive temperature zones A, B, and, in long-term operation, as a measure to counteract the reduction in the quality of the fixed catalyst bed, the temperature of at least one of the two temperature zones is increased such that the difference TB−TA becomes increasingly greater, where TB is the temperature of temperature zone B, and TA the temperature of temperature zone A.
摘要:
The present invention relates to a multilayer catalyst for preparing phthalic anhydride which has a plurality of catalyst layers arranged in succession in the reaction tube, with the individual catalyst layers having alkali metal contents which decrease in the flow direction. The present invention further relates to a process for the oxidation of naphthalene or o-xylene/naphthalene mixtures over such a multilayer catalyst and the use of such multilayer catalysts for the oxidation of naphthalene or o-xylene/naphthalene mixtures to phthalic anhydride.