Special Issue "Aerogel Catalyst"
A special issue of Catalysts (ISSN 2073-4344).
Deadline for manuscript submissions: closed (30 September 2012)
Dr. Theophilos Ioannides
Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Stadiou Str., Platani, P.O. Box 1414, GR-26504 Patras, Greece
Phone: +30 2610 965 264
Fax: +30 2610 965 223
Interests: heterogeneous catalysts; catalytic Processes; new materials; membrane processes
Dr. Nathalie Job
Département de Chimie appliquée, Bât. B6, Université de Liège, Allée de la Chimie 3, 4000 Liège 1, Belgium
The term aerogel describes a material obtained by supercritical extraction of the liquid of a gel, itself consisting of a solid three-dimensional network that ensnares a liquid medium. Drying by transition from the liquid to the supercritical phase does away with the capillary forces, which act in evaporation and cause partial or total collapse of the pore network. Hence, supercritical drying leads to materials with low density, high specific surface area, large pore volume and very versatile pore size. The first aerogels were produced from silica gels in 1937. Since then, the sol-gel technique has expanded to other inorganic materials such as alumina or titanium oxide, for instance, then to carbon in the late 1980s.
Extending the original definition, literature includes in aerogel-like materials a large variety of nanostructured porous solids. One can cite, for instance, materials obtained by supercritical drying of precipitates, which maintain a loose structure with non-agglomerated primary particles. Cryogels synthesized by freeze-drying of gels, or xerogels, i.e. materials prepared via subcritical drying but that nevertheless maintain a substantial fraction of the original gel pore texture, constitute an interesting alternative to the (costly) supercritical drying.
The inherent properties of aerogels and aerogel-like supports render them very attractive in catalytic applications, as shown by the constantly renewed interest of research groups for this technology through the years. Besides high dispersion of the active phase, made possible by high surface areas, the high pore volume and tunable pore size of aerogels lead to the possibility of designing catalyst supports that facilitate the diffusion of reactants and products to and from the active sites. The indubitable improvements in catalytic performance obtained through use of aerogel supports should of course outweigh their higher processing cost. To this end, the development of efficient manufacture processes is crucial and should constitute the last step towards large-scale use of catalysts supported on these fascinating engineered supports.
Dr. Theophilos Ioannides
Dr. Nathalie Job
- catalyst supports
- nanostructured materials
Catalysts 2013, 3(1), 11-26; doi:10.3390/catal3010011
Received: 2 October 2012; in revised form: 5 December 2012 / Accepted: 8 January 2013 / Published: 16 January 2013| Download PDF Full-text (2490 KB) | View HTML Full-text | Download XML Full-text
Article: Tailoring Synthesis Conditions of Carbon Xerogels towards Their Utilization as Pt-Catalyst Supports for Oxygen Reduction Reaction (ORR)
Catalysts 2012, 2(4), 466-489; doi:10.3390/catal2040466
Received: 6 August 2012; in revised form: 24 September 2012 / Accepted: 9 October 2012 / Published: 17 October 2012| Download PDF Full-text (881 KB) | View HTML Full-text | Download XML Full-text
Catalysts 2012, 2(4), 447-465; doi:10.3390/catal2040447
Received: 20 July 2012; in revised form: 28 September 2012 / Accepted: 9 October 2012 / Published: 17 October 2012| Download PDF Full-text (467 KB) | View HTML Full-text | Download XML Full-text
Article: Carbon Aerogel-Supported Pt Catalysts for the Hydrogenolysis and Isomerization of n-Butane: Influence of the Carbonization Temperature of the Support and Pt Particle Size
Catalysts 2012, 2(4), 422-433; doi:10.3390/catal2040422
Received: 18 July 2012; in revised form: 3 September 2012 / Accepted: 24 September 2012 / Published: 12 October 2012| Download PDF Full-text (307 KB) | View HTML Full-text | Download XML Full-text
Catalysts 2012, 2(3), 386-399; doi:10.3390/catal2030386
Received: 1 August 2012; in revised form: 6 September 2012 / Accepted: 7 September 2012 / Published: 19 September 2012| Download PDF Full-text (1567 KB) | View HTML Full-text | Download XML Full-text
Article: Large Mesopore Generation in an Amorphous Silica-Alumina by Controlling the Pore Size with the Gel Skeletal Reinforcement and Its Application to Catalytic Cracking
Catalysts 2012, 2(3), 368-385; doi:10.3390/catal2030368
Received: 28 June 2012; in revised form: 27 August 2012 / Accepted: 31 August 2012 / Published: 13 September 2012| Download PDF Full-text (1648 KB) | View HTML Full-text | Download XML Full-text | Supplementary Files
Last update: 25 February 2014