{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/54344"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/54344","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Element substituted aluminophosphates","abstract":"This dissertation reports the findings of an investigation aiming to the incorporation of the transition elements: cobalt, vanadium, and molybdenum into AlPO₄-5 molecular sieves, to the study of the redox properties of the resulting materials and to the potential application of these compounds in the partial oxidation of methane to methanol and formaldehyde. AlPO₄-5 molecular sieves containing Co, V, and Mo were synthesized by hydrothermal crystallization of typical aluminophosphate gels with the adequate metal substrates at temperatures of 200°C, 150°C, and 150°C respectively. Samples of each material were calcined in oxidant, reducing and inert atmospheres and the properties of the treated solids studied by different characterization techniques. The significant feature of the Co and V containing AlPO₄-5, CoAPO-5 and VAPO-5, is that they exhibit different colors depending on the treatment atmosphere. Evidence for cobalt contained in framework positions of CoAPO-5 is obtained by the change in its unit cell volume relative to AlPO₄-5, and by diffuse reflectance spectroscopy. CoAPO-5 also contains an appreciable quantity of extra-framework cobalt occluded in the pores, and/or as balancing cations. Evidence for this was obtained from ion exchange, and from oxygen and argon adsorption. Pentavalent vanadium incorporation is inferred from the change in the unit cell volume of VAPO-5 relative to AlPO₄-5, from pH measurements of the reaction vessel contents before and after heating, from oxygen and argon adsorption, chemical analysis, SEM, XPS, NMR, and diffuse reflectance spectroscopy. A scheme for the substitution of V into AlPO₄-5 is postulated based on the acidity observed in VAPO-5 by ion exchange, and potentiometrlc titration. Only a very small amount of Mo was found in the molybdenum containing AlPO₄-5. Evidence for Mo incorporation into the framework was not obtained. The use of CoAPO-5 and VAPO-5 as redox catalysts for the partial oxidation of methane to methanol and formaldehyde lead mostly to oxides of carbon.","abstract_html":"This dissertation reports the findings of an investigation aiming to the incorporation of the transition elements: cobalt, vanadium, and molybdenum into AlPO₄-5 molecular sieves, to the study of the redox properties of the resulting materials and to the potential application of these compounds in the partial oxidation of methane to methanol and formaldehyde. AlPO₄-5 molecular sieves containing Co, V, and Mo were synthesized by hydrothermal crystallization of typical aluminophosphate gels with the adequate metal substrates at temperatures of 200°C, 150°C, and 150°C respectively. Samples of each material were calcined in oxidant, reducing and inert atmospheres and the properties of the treated solids studied by different characterization techniques. The significant feature of the Co and V containing AlPO₄-5, CoAPO-5 and VAPO-5, is that they exhibit different colors depending on the treatment atmosphere. Evidence for cobalt contained in framework positions of CoAPO-5 is obtained by the change in its unit cell volume relative to AlPO₄-5, and by diffuse reflectance spectroscopy. CoAPO-5 also contains an appreciable quantity of extra-framework cobalt occluded in the pores, and/or as balancing cations. Evidence for this was obtained from ion exchange, and from oxygen and argon adsorption. Pentavalent vanadium incorporation is inferred from the change in the unit cell volume of VAPO-5 relative to AlPO₄-5, from pH measurements of the reaction vessel contents before and after heating, from oxygen and argon adsorption, chemical analysis, SEM, XPS, NMR, and diffuse reflectance spectroscopy. A scheme for the substitution of V into AlPO₄-5 is postulated based on the acidity observed in VAPO-5 by ion exchange, and potentiometrlc titration. Only a very small amount of Mo was found in the molybdenum containing AlPO₄-5. Evidence for Mo incorporation into the framework was not obtained. The use of CoAPO-5 and VAPO-5 as redox catalysts for the partial oxidation of methane to methanol and formaldehyde lead mostly to oxides of carbon.","abstract_has_math":false,"creators":["Correa, Maria del Consuela Montes de"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Chemical Engineering","degree_department":"Chemical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Davis, Mark E."],"committee_members":["Gibbs, Gerald","Cox, David","Wills, George B.","Conger, William L."],"year":1989,"date_issued":"1989","date_published":"1989","updated_at":"2026-07-22T22:18:47Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/54344","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Davis, Mark E."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Gibbs, Gerald","Cox, David","Wills, George B.","Conger, William L."]},{"key":"dc:contributor.department","label":"Department","values":["Chemical Engineering"]},{"key":"dc:creator","label":"Author","values":["Correa, Maria del Consuela Montes de"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2015-07-09T20:43:47Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2015-07-09T20:43:47Z"]},{"key":"dc:date.issued","label":"Date","values":["1989"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. 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AlPO₄-5 molecular sieves containing Co, V, and Mo were synthesized by hydrothermal crystallization of typical aluminophosphate gels with the adequate metal substrates at temperatures of 200°C, 150°C, and 150°C respectively. Samples of each material were calcined in oxidant, reducing and inert atmospheres and the properties of the treated solids studied by different characterization techniques. The significant feature of the Co and V containing AlPO₄-5, CoAPO-5 and VAPO-5, is that they exhibit different colors depending on the treatment atmosphere. Evidence for cobalt contained in framework positions of CoAPO-5 is obtained by the change in its unit cell volume relative to AlPO₄-5, and by diffuse reflectance spectroscopy. CoAPO-5 also contains an appreciable quantity of extra-framework cobalt occluded in the pores, and/or as balancing cations. Evidence for this was obtained from ion exchange, and from oxygen and argon adsorption. Pentavalent vanadium incorporation is inferred from the change in the unit cell volume of VAPO-5 relative to AlPO₄-5, from pH measurements of the reaction vessel contents before and after heating, from oxygen and argon adsorption, chemical analysis, SEM, XPS, NMR, and diffuse reflectance spectroscopy. A scheme for the substitution of V into AlPO₄-5 is postulated based on the acidity observed in VAPO-5 by ion exchange, and potentiometrlc titration. Only a very small amount of Mo was found in the molybdenum containing AlPO₄-5. Evidence for Mo incorporation into the framework was not obtained. The use of CoAPO-5 and VAPO-5 as redox catalysts for the partial oxidation of methane to methanol and formaldehyde lead mostly to oxides of carbon."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Element substituted aluminophosphates"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Davis, Mark E."],"dc:contributor.committeemember":["Gibbs, Gerald","Cox, David","Wills, George B.","Conger, William L."],"dc:contributor.department":["Chemical Engineering"],"dc:creator":["Correa, Maria del Consuela Montes de"],"dc:date.accessioned":["2015-07-09T20:43:47Z"],"dc:date.available":["2015-07-09T20:43:47Z"],"dc:date.issued":["1989"],"dc:description.abstract":["This dissertation reports the findings of an investigation aiming to the incorporation of the transition elements: cobalt, vanadium, and molybdenum into AlPO₄-5 molecular sieves, to the study of the redox properties of the resulting materials and to the potential application of these compounds in the partial oxidation of methane to methanol and formaldehyde. AlPO₄-5 molecular sieves containing Co, V, and Mo were synthesized by hydrothermal crystallization of typical aluminophosphate gels with the adequate metal substrates at temperatures of 200°C, 150°C, and 150°C respectively. Samples of each material were calcined in oxidant, reducing and inert atmospheres and the properties of the treated solids studied by different characterization techniques. The significant feature of the Co and V containing AlPO₄-5, CoAPO-5 and VAPO-5, is that they exhibit different colors depending on the treatment atmosphere. Evidence for cobalt contained in framework positions of CoAPO-5 is obtained by the change in its unit cell volume relative to AlPO₄-5, and by diffuse reflectance spectroscopy. CoAPO-5 also contains an appreciable quantity of extra-framework cobalt occluded in the pores, and/or as balancing cations. Evidence for this was obtained from ion exchange, and from oxygen and argon adsorption. Pentavalent vanadium incorporation is inferred from the change in the unit cell volume of VAPO-5 relative to AlPO₄-5, from pH measurements of the reaction vessel contents before and after heating, from oxygen and argon adsorption, chemical analysis, SEM, XPS, NMR, and diffuse reflectance spectroscopy. A scheme for the substitution of V into AlPO₄-5 is postulated based on the acidity observed in VAPO-5 by ion exchange, and potentiometrlc titration. Only a very small amount of Mo was found in the molybdenum containing AlPO₄-5. Evidence for Mo incorporation into the framework was not obtained. The use of CoAPO-5 and VAPO-5 as redox catalysts for the partial oxidation of methane to methanol and formaldehyde lead mostly to oxides of carbon."],"dc:description.degree":["Ph. D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/54344"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Element substituted aluminophosphates"],"dc:type":["Dissertation"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Chemical Engineering"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:47Z"}