Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.571733
Title: Methanol oxidation on transition elements oxides
Author: Alshehri, Abdulmohsen
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2013
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Abstract:
Methanol oxidation to formaldehyde is one of the most important industries in our lives; the reaction occurs on catalyst surface in heterogeneous catalysis. Iron molybdate is the current selective catalyst. However, molybdenum volatilises during methanol oxidation and leaving the catalyst with a low molybdenum ratio, which deactivates the catalyst, a 2.2 Mo: 1Fe iron molybdate catalyst was used instead the stoichiometric catalyst, while yield of formaldehyde cannot be 100%. The goal of this study is to find more selective and more productive catalyst than iron molybdate catalyst, the first step is to find another transition element as selective as molybdenum, because molybdenum is the selective part, and iron is the active part, the resulting iron molybdate catalyst is a selective catalyst to formaldehyde near molybdenum and active near iron. Experimentally, catalysts were prepared using co-precipitation method, however, some doped catalysts were papered by incipient wetness impregnation, also sol-immobilization was used to prepare nano-gold particles on the surfaces of few supports. Catalysts characterizations were carried out within several techniques for the surface analysis (XPS) and bulk analysis (XRD), also the surface area was measured by BET equipment. Raman too was used in this study, while micro-reactor was the reactor to determine selectivity and activity of each catalyst. When molybdenum replaced by vanadium, the catalyst yielded 100% formaldehyde at 200 oC; moreover, tungsten was selective. Likewise, iron was replaced by other active metals such as manganese, copper and bismuth, which are active. Nano-gold improved activity when doped on molybdenum oxide and iron molybdate supports.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.571733  DOI: Not available
Keywords: QD Chemistry
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