Special Issue "New Trends in Gold Catalysts"

Guest Editor
Dr. Leonarda F. Liotta
Institute of Nanostructured Materials, Palermo Research Division, CNR - ISMN, via Ugo La Malfa 153, 90146 Palermo, Italy
Website: http://www.pa.ismn.cnr.it/liotta.htm
E-Mail: liotta@pa.ismn.cnr.it
Phone: +39 091 6809371
Fax: +39 091 6809399
Interests: synthesis; characterization and structure-activity relationship of supported noble metal (Pt,Pd, Au) for oxidation reactions; metal-support interaction in gold catalysts for low-temperature CO and VOCs oxidation; use of gold for hydrogen purification by selective oxidation of carbon monoxide (PROX); development of Pd and Au catalysts for abatement at low temperature of VOCs and methane emitted by mobile sources; synthesis and characterization of bimetallic Ni-Au catalysts for hydrocarbon steam reforming reaction and syngas production; optimization of Co-based catalysts composition and preparation method for Fischer-Tropsch synthesis

Dear Colleagues,

The growing importance of the catalysis by gold is nowadays proved by the promising applications in several fields, such as green chemistry, enantioselective synthesis, environmental catalysis, hydrogen production and purification as well. This special issue “New Trends in Gold catalysts” aims to cover the numerous aspects in the use of gold as main active site as well as in the use of small amount of gold as promoting the activity of transition metals catalysts. In details, the following topics will be addressed: synthesis, characterization and structure-activity relationship of supported mono and bi-metallic (Au-M) catalysts for oxidation reactions; metal-support interaction in gold catalysts for low-temperature CO, VOCs and soot oxidation; synthesis of adipic acid as target product for polyamides manufacturing; use of gold for hydrogen purification by selective oxidation of carbon monoxide (PROX) and for hydrogen production (WGSR); development of Au catalysts for abatement at low temperature of VOCs and methane emitted by mobile sources; synthesis and characterization of supported mono- and bimetallic (M-Au) catalysts for methane dry reforming reaction; optimization of Co-based catalysts composition and preparation method for Fischer-Tropsch synthesis; selective hydrogenation of butadienes for olefin streams purification.

Dr. Leonarda F. Liotta
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Catalysts is an international peer-reviewed Open Access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 300 CHF (Swiss Francs). English correction and/or formatting fees of 250 CHF (Swiss Francs) will be charged in certain cases for those articles accepted for publication that require extensive additional formatting and/or English corrections.

• Au
• Au-M (M = Pd, Pt, Ni, Fe, Co)
• metal-support interaction
• oxygen vacancy
• CO
• VOCs
• soot oxidation
• PROX
• WGSR
• Fischer-Tropsch synthesis
• methane dry reforming
• selective hydrogenation

Type of Paper: Review
Title: Ni-based Catalysts for Low Temperature Methane steam Reforming: Recent Results on Metal Additives Effects
Authors: H. Wu ^1,2, L.F. Liotta ¹, V. La Parola ¹, G. Pantaleo ¹, A.M. Venezia ¹
Affiliations: ¹ Istituto per lo Studio di Materiali Nanostrutturati (ISMN)-CNR, Via Ugo La Malfa 153, 90146 Palermo, Italy; E-Mail: liotta@pa.ismn.cnr.it
² Department of Applied Physics, Northwestern Polytechnical University (NPU), 127 Youyi Xilu, 710072, Xi’an, China
Abstract: Steam reforming of light hydrocarbon provides a promising method for hydrogen production. Ni-based catalysts are so far the best and the most commonly used catalysts for steam reforming because of their acceptably high activity and significantly lower cost in comparison with alternative precious metal-based catalysts. However, nickel catalysts are susceptible to deactivation from the deposition of carbon, even when operating at steam-to-carbon ratios predicted to be thermodynamically outside of the carbon-forming regime. Reactivity and deactivation by carbon formation can be tuned by modifying Ni surfaces with a second metal such as gold or silver through alloy formation. Moreover, modification of support, like alumina, by CeO₂ and or by La₂O₃ is known to reduce coke deposition over Ni supported catalysts or to stabilize Ni particles against sintering. erein, in the present review, we summarize the very recent progresses in the design, synthesis, and characterization of supported bimetallic Ni-based catalysts for steam reforming. The progresses in the use of second metal as well as in the support modification, in the preparation and pretreatment methods have been discussed. The differences of catalytic activity, thermal stability and carbon species between bimetallic and monometallic Ni-based catalysts are also briefly compared.
Keywords: steam reforming; nickel; gold; bimetallic; surface alloy; support modification

Type of Paper: Article
Title: Formation and Catalysis of the Thermally Stable Au Nanoparticles Generated on Dealumiated Y Zeolites
Author: Kazu Okumura
Affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Koyama-cho, Minami, Tottori680-8552, Japan
Abstract: Gold was deposited on the USY zeolite with an ion-exchange method. Up to 5.5 wt% Au was introduced to the USY zeolite when NH4-form was employed for the loading of Au. In contrast, deposition of Au hardly took place on H-, Na-forms of Y-type zeolite and ammonium-forms of mordenite and ZSM-5. Treatment of the Au loaded USY zeolite in the atmosphere of hydrogen afforded the Au0 nanoparticles. The Au nanoparticle was thermally stable at 973 K where the mean diameter of the particle was 3.7 nm. In contrast to this, formation of severely aggregated Au particle was observed after thermal treatment at 473 K, followed by storing in air for a month. The Au0 particle size was in good correlation with the intensity of the IR band of adsorbed CO and the catalytic activity in aerobic oxidation of
benzyl alcohol; the highest activity was obtained after Au/USY zeolite was thermally treated at 673-973 K. No deactivation was observed after repetition of the reaction at least 12 times. This study demonstrated the potential use of NH4-form USY-type zeolite for the support for Au.

Type of Paper: Article
Title: Investigation on the Stability of Supported Gold Nanoparticles
Author: M. Signoretto ¹, F. Menegazzo ¹, F. Pinna ¹, M. Manzoli ² and F. Boccuzzi ²
Affiliation:¹ Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice and Consortium INSTM UdR Ve, Dorsoduro 2137, 30123 Venice, Italy
² Department of Chemistry, University of Turin, and NIS Centre of Excellence, via P. Giuria 7, 10125 Torino, Italy
Abstract: Procedures leading to the preservation of catalytic performances of Au/ZrO₂ samples will be investigated. Both the two potential causes of deactivation, namely the particle growth by sintering of gold nanoparticles and the formation of unreactive species which inhibit the reaction, will be evaluated in depth. In particular, the paper will consider: (i) the stability under storage conditions; (ii) the stability with time on stream for a gas phase reaction (LT-WGSR); (iii) the stability with time on stream for a liquid phase reaction (furfural oxidative esterification). 0.5 wt%–1 wt%–3 wt% gold-loaded zirconia and sulphated zirconia catalysts were synthesised by deposition-precipitation method and calcined at different temperatures in the 298–923 K range, in order to investigate samples with various metal amount and gold nanosize. Fresh and exhausted samples were characterized by N₂ adsorption analysis, A.A., IC, TPR, TPO, XRD, pulse-flow CO chemisorption, FTIR spectroscopy and HRTEM.
Keywords: gold nanoparticles; stability, sulphated zirconia; FTIR spectroscopy; LT-WGS reaction; oxidative esterification; furfural