Author
José J.M. Órfão
Other affiliations: Faculdade de Engenharia da Universidade do Porto, Instituto Superior de Engenharia do Porto
Bio: José J.M. Órfão is an academic researcher from University of Porto. The author has contributed to research in topics: Catalysis & Activated carbon. The author has an hindex of 58, co-authored 175 publications receiving 13411 citations. Previous affiliations of José J.M. Órfão include Faculdade de Engenharia da Universidade do Porto & Instituto Superior de Engenharia do Porto.
Topics: Catalysis, Activated carbon, Carbon, Adsorption, Oxalic acid
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a deconvolution method is proposed to analyze the TPD spectra, allowing for the quantitative determination of the amount of each functional group on the surface. But the deconvolutions are not suitable for the analysis of a large number of functional groups.
2,674 citations
TL;DR: In this paper, the behavior of biomass components (cellulose, xylan, and lignin) was studied thermogravimetrically with linear temperature programming, under nitrogen and air.
748 citations
TL;DR: It is shown that the surface chemistry of the activated carbon plays a key role in dye adsorption performance, with the basic sample obtained by thermal treatment under H(2) flow at 700 degrees C is the best material for the adsorbed dyes.
696 citations
TL;DR: In this paper, a series of manganese oxides differing in the structure, composition, average menganese oxidation state and specific surface area have been used in the total oxidation of volatile organic compounds (VOC).
Abstract: A series of manganese oxides differing in the structure, composition, average manganese oxidation state and specific surface area have been used in the total oxidation of volatile organic compounds (VOC). Ethanol, ethyl acetate and toluene were chosen as models of VOC. Among the manganese oxides tested, cryptomelane (KMn8O16) was found to be very active in the oxidation of VOC. The performance of cryptomelane was significantly affected by the presence of other phases, namely, Mn2O3 and Mn3O4. Temperature-programmed experiments combined with X-ray photoelectron spectroscopy (XPS) show that the mobility and reactivity of the oxygen species were significantly affected, explaining the catalytic performances of those samples. Mn3O4 improves the catalytic performance due to the increase of the reactivity and mobility of lattice oxygen, while Mn2O3 has the opposite effect. These results show that there is a correlation between the redox properties and the catalytic performance of the manganese oxides. Temperature-programmed surface reactions (TPSR) after adsorption of toluene or ethanol, in addition to reactions performed without oxygen in the feed, show that lattice oxygen is involved in the VOC oxidation mechanism. The conversion level was found to be influenced by the type of VOC, the reactivity into CO2 increasing in the following order: Toluene
553 citations
TL;DR: In this article, the surface chemistry of commercial activated carbon has been selectively modified, without changing significantly its textural properties, by means of chemical treatments, using HNO 3, H 2 O 2, NH 3, and thermal treatments under a flow of H 2 or N 2.
545 citations
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TL;DR: Hydrogen Production by Water−Gas Shift Reaction 4056 4.1.
Abstract: 1.0. Introduction 4044 2.0. Biomass Chemistry and Growth Rates 4047 2.1. Lignocellulose and Starch-Based Plants 4047 2.2. Triglyceride-Producing Plants 4049 2.3. Algae 4050 2.4. Terpenes and Rubber-Producing Plants 4052 3.0. Biomass Gasification 4052 3.1. Gasification Chemistry 4052 3.2. Gasification Reactors 4054 3.3. Supercritical Gasification 4054 3.4. Solar Gasification 4055 3.5. Gas Conditioning 4055 4.0. Syn-Gas Utilization 4056 4.1. Hydrogen Production by Water−Gas Shift Reaction 4056
7,067 citations
TL;DR: In this article, the pyrolysis characteristics of three main components (hemicellulose, cellulose and lignin) of biomass were investigated using, respectively, a thermogravimetric analyzer (TGA) with differential scanning calorimetry (DSC) detector and a pack bed.
5,859 citations
TL;DR: It is evident from a literature survey of about 210 recent papers that low-cost sorbents have demonstrated outstanding removal capabilities for certain dyes, and chitosan might be a promising adsorbent for environmental and purification purposes.
3,906 citations
TL;DR: From a comprehensive literature review, it was found that some LCAs, in addition to having wide availability, have fast kinetics and appreciable adsorption capacities too.
3,163 citations
TL;DR: In this article, a review of the recent developments in the synthesis of adsorbents containing polysaccharides, in particular modified biopolymers derived from chitin, chitosan, starch and cyclodextrin, is presented.
1,939 citations