Characterization of the porosity developed in a new titania-alumina catalyst support prepared by the sol gel route

Titanium oxide (TiO2) is a good candidate for support of hydrotreating catalysts but has the disadvantage of presenting a low surface area and a poor thermal stability when compared with Al2O3. A mixed TiO2-Al2O3 support was proposed as an alternative that is expected to be free from these drawbacks. The variation during firing of the nanoporous texture of supports composed of TiO2-Al2O3, TiO2 and Al2O3 was studied by small angle X-ray scattering (SAXS). The supports were prepared by the sol-gel route using Ti and Al isopropoxides. We have particularly analyzed the effects of acid and basic hydrolysis on the nanostructural features of catalyst supports fired at different temperatures. The nanopore radius distribution functions were determined from SAXS results assuming a simple model of spherical nanopores embedded in a homogeneous solid matrix. The modal pore radius in both pure TiO2 and pure Al2O3 supports grows from 1.3 to 2.2 nm as the firing temperature increases from 673 to 973 K. on the other hand, the modal pore radius in the mixed TiO2-Al2O3 support remains below 1.2 nm over the same range of firing temperatures. These results demonstrate the good thermal stability of the nanoporous texture of mixed TiO2-Al2O3 supports.

Reestructuración y revitalización de las Naciones Unidas en las esferas económica y social: papel y funciones de la CEPAL = Restructuring and revitalization of the United Nations in the economic and social fields: role and functions of ECLAC = Restructuration et revitalisation de l'Organisation des Nations Unies dans les domaines économique et social: rôle et fonctions de la CEPALC

Incluye Bibliografía

Reestructuración y revitalización de las Naciones Unidas en las esferas económica y social: información actualizada sobre sus consecuencias para la Comisión Económica para América Latina y el Caribe = Restructuring and revitalization of the United Nations in the economic and social fields: an update on its impact on the Economic Commission for Latin America and the Caribbean = Restructuration et revitalisation de l'Organisation des Nations Unies dans les domaines économique et social: information actualisée sur les repercussions pour la CEPALC

Incluye Bibliografía

The native flowers and ferns of the United States in their botanical, horticultural and popular aspects / by Thomas Meehan ; illustrated by chromolithographs.

2

United States code : containing the general and permanent laws of the United States in force on January 3,1941 /

Mode of access: Internet.

Agriculture of the United States in 1860;

Mode of access: Internet.

Middle Atlantic Interstate Forest Fire Protection Compact to include the state of Ohio; land conveyance in Henderson, TN; and release a revisionary interest of the United States in certain land located in Oktibbeha County, MS [microform] : hearings before the Subcommittee on Forests, Family Farms, and Energy of the Committee on Agriculture, House of Representatives, One Hundredth Congress, second session, on H.R. 2756, H.R. 2835, and H.R. 4724, May 4, 1988 ... September 22, 1988 ....

"Serial no. 100-89."

The balance of international payments of the United States in 1922-

1932 includes Summary tables, 1919-1932.

James R. Mann. Memorial addresses delivered in the House of Representatives of the United States in memory of James R. Mann, late a representative from Illinois. Sixty-seventh Congress. January 14, 1923.

"Proceedings in the Senate": p. 109-[113]

Henry D. Flood. Memorial addresses delivered in the House of representatives of the United States in memory of Henry D. Flood, late a representative from Virginia.

Running title: Memorial addresses. Representative Flood.

Senators from Pennsylvania. Memorial addresses delivered in the Senate and House of Representatives of the United States in memory of Philander C. Knox, Boies Penrose, William E. Crow, late senators from Pennsylvania. Sixty-seventh Congress. Proceedings in the Senate, January 28, 1923. Proceedings in the House, February 18, 1923.

Running title: Memorial addresses.