Catalyst In Presence Of Water Research Articles

Furfuryl Alcohol and Furfural Hydrogenation over Activated Carbon–supported Palladium Catalyst in Presence of Water and Carbon Dioxide

AbstractHydrogenation of furfuryl alcohol and furfural over an activated carbon‐supported palladium catalyst was carried out and the effects of solvent and carbon dioxide on the activity and selectivity of the reactions were studied. For the hydrogenation of furfuryl alcohol and furfural, the addition of protic solvents led to a higher initial activity compared to that under neat conditions. Among the protic solvents, water caused the highest increase in the initial activities. When carbon dioxide was added to protic solvents, the initial activities increased further. For a system containing both water and carbon dioxide, the initial activity increased when the pressure of carbon dioxide introduced was increased up to 10 MPa, after which the activity remained almost constant. The results of the hydrogenation of furfural over the supported palladium catalyst showed that tetrahydrofurfural and furfuryl alcohol were the initial products; furfuryl alcohol was subsequently reduced to tetrahydrofurfuryl alcohol.

Catalytic ozonation of clofibric acid over copper-based catalysts: In situ ATR-IR studies

The current study describes the catalytic ozonation of clofibric acid (CFA) under ambient conditions using copper oxide catalysts synthesized by different methods. The objective of this study is to provide novel catalysts and reaction mechanism for the degradation of emerging pharmaceutical compounds in aqueous solution. Among the various Cu catalysts screened in this study, the Cu1–Al1 oxide catalyst showed an excellent activity and stability in the degradation and mineralization of CFA. In situ attenuated total reflection IR (ATR-IR) spectroscopy was used to examine the interaction of ozone with the active sites of the catalyst in presence of water and to investigate the possible catalytic mechanism. The presence of Lewis acid sites in the Cu1–Al1 catalyst increased the amount of chemisorbed water enhancing stronger interaction of ozone to form surface activated species, resulting in higher catalytic activity. The results obtained from in -situ ATR-IR study indicate that surface hydroxyl groups and Lewis acid sites are responsible for promoting the generation of hydroxyl radicals (OH) from aqueous ozone.

Steam reforming, partial oxidation and oxidative steam reforming for hydrogen production from ethanol over cerium nickel based oxyhydride catalyst

H2 production from ethanol was studied on a cerium nickel based (CeNi1OY) catalyst in presence of water (SRE), in presence of oxygen with different concentrations (POE) and in presence of oxygen and water (OSRE). The influence of different parameters was analyzed, such as the reaction temperature, reactants concentration (oxygen/ethanol/water), and in situ pre-treatment in H2. At low temperature a high activity i.e., ethanol conversion and H2 formation can be obtained when the solid is previously in situ treated in H2 at 250°C i.e., in the oxyhydride form. Adding O2 allows increasing ethanol conversion at low temperature. Different physicochemical techniques, including Inelastic Neutron Scattering (INS), were used to characterize the catalyst. An active site based on the formation of anionic vacancies and a mechanism involving a heterolytic abstraction of a hydride species from ethanol are envisaged.

Laser-enhanced photocatalytic degradation of organic pollutants from water using ZnO semiconductor catalyst

Wastewater contaminated with organic pollutants creates serious environmental problems. Laser induced photocatalysis has been investigated for removal of organic pollutant like phenol from water. The important mechanism for degradation of phenol by UV laser irradiation is redox reactions triggered by semiconductor catalyst in presence of water. In this study the potential of a ZnO semiconductor catalyst has been explored as an effective catalyst for the photodegradation of phenol using a Nd:YAG laser-emitting at 355 nm in UV-radiation in a batch reactor. The influences of different parameters such as catalyst concentration, UV-radiation intensity, and pH on the extent of photo degradation have been investigated. Overall degradation of phenol achieved was 70% after 60 minutes of laser irradiation of 100 ppm phenol solution in water. The reaction rate constant fit a first-order reaction model for phenol degradation and was estimated as 0.0088 min− 1. This study proved that laser induced photocatalytic removal of phenol is highly efficient as compared with the broadband spectral sources such as lamps being applied in majority of setups worldwide.

ChemInform Abstract: The Alkylation of Methylphenols by Methanol on Aluminium‐Vanadium Catalyst in Presence of Water.

Chemischer InformationsdienstVolume 17, Issue 17 Preparative Organic Chemistry ChemInform Abstract: The Alkylation of Methylphenols by Methanol on Aluminium-Vanadium Catalyst in Presence of Water. V. N. KORENSKII, V. N. KORENSKIISearch for more papers by this authorI. P. KOLENKO, I. P. KOLENKOSearch for more papers by this authorV. N. VINOGRADOVA, V. N. VINOGRADOVASearch for more papers by this authorG. D. KHARLAMPOVICH, G. D. KHARLAMPOVICHSearch for more papers by this authorE. I. LOGINOVA, E. I. LOGINOVASearch for more papers by this author V. N. KORENSKII, V. N. KORENSKIISearch for more papers by this authorI. P. KOLENKO, I. P. KOLENKOSearch for more papers by this authorV. N. VINOGRADOVA, V. N. VINOGRADOVASearch for more papers by this authorG. D. KHARLAMPOVICH, G. D. KHARLAMPOVICHSearch for more papers by this authorE. I. LOGINOVA, E. I. LOGINOVASearch for more papers by this author First published: April 29, 1986 https://doi.org/10.1002/chin.198617161AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume17, Issue17April 29, 1986 RelatedInformation