Daniel E. Damiani

Bio: Daniel E. Damiani is an academic researcher from National Scientific and Technical Research Council. The author has contributed to research in topics: Catalysis & Methylaluminoxane. The author has an hindex of 17, co-authored 62 publications receiving 947 citations.

On the role of Pd β-hydride in the reduction of nitrate over Pd based catalyst

Abstract: Two monometallic palladium catalysts supported on γ-Al2O3 were synthesized using different precursors, Pd(AcAc)2 and Pd(NO3)2, while Pd-Cu/γ Al2O3 catalysts were prepared from those parent catalysts. The samples were tested for the elimination of nitrate and nitrite from aqueous solutions using hydrogen as a reductant in a standard batch reactor. Besides, the reduction of nitrate was carried out in a series of two reactors by an electrochemical cell mechanism. In this case, nitrate was reduced to nitrite by electrons supplied from the first reactor. The following reduction of nitrite was performed over the monometallic catalyst. Both the conversion and the selectivity to N2 were higher than in the standard batch reactor. Monometallic samples prepared from Pd(AcAc)2 showed an extremely high selectivity to the desired product. The catalysts were characterized by transmission electron microscopy (TEM), temperature programmed reduction (TPR) and H2 chemisorption. Differences in particle size and β-hydride formation were observed for the different samples. The possible role of Pd β-hydride in the formation of overhydrogenated products is discussed.

Zinc carboxylic salts used as catalyst in the biodiesel synthesis by esterification and transesterification: Study of the stability in the reaction medium

Abstract: Biodiesel is produced by the catalytic transesterification of renewable sources such as vegetable oils and animal fats. It is an attractive alternative to diesel fuel because of its environmental benefits. In this work, the transesterification of soybean oil with methanol using zinc carboxylic salts as Lewis acid catalysts was studied. The esterification of fatty acids was also researched. In both reactions, the stability of the catalyst in the reaction medium was examined. Zinc carboxylic salts of different chain lengths, Zn(CnH2n+1COO)2 with n = 1, 11, 15, and 17, and Zn(C17H33COO)2 (zinc(II) acetate, laurate, palmitate, stearate and oleate, respectively) were prepared and characterized by X-ray diffraction, FTIR spectrometry and thermogravimetric analysis. The Zn salts were tested in the transesterification of soybean oil at 100 °C for 2 h. They presented oil conversions between 88 and 94% with fatty acid methyl ester (FAME) yields between 71 and 74%, and they were stable in three consecutive tests. Zn acetate was not stable. The salts transformed into Zn glycerolate at 140 °C in the reaction medium (zinc laurate, palmitate, and stearate only partially). It was observed that, in the presence of fatty acids, the carboxylates of the salts were gradually exchanged for the acid to be esterified. With oleic acid, this process was completed at 60 °C for all the Zn(CnH2n+1COO)2 salts. Zinc laurate, palmitate and stearate are crystalline solids, but soluble in the reaction medium at 100 °C, and they recrystallize rapidly at room temperature, presenting certain advantages as regards decreasing mass transfer resistance during reaction, and easy separation and recovery from reaction medium.

Design and fabrication of mesoporous heterogeneous basic catalysts

Abstract: Mesoporous solid bases are extremely desirable in green catalytic processes, due to their advantages of accelerated mass transport, negligible corrosion, and easy separation. Great progress has been made in mesoporous solid bases in the last decade. In addition to their wide applications in the catalytic synthesis of organics and fine chemicals, mesoporous solid bases have also been used in the field of energy and environmental catalysis. Development of mesoporous solid bases is therefore of significant importance from both academic and practical points of view. In this review, we provide an overview of the recent advances in mesoporous solid bases, which is basically grouped by the support type and each category is illustrated with typical examples. Cooperative catalysts derived from the incorporation of additional functionalities (i.e. acid and metal) into mesoporous solid bases are also included. The fundamental principles of how to design and fabricate basic materials with mesostructure are highlighted. The mechanism of the formation of basic sites in different mesoporous systems is discussed as well.

A Review of Molybdenum Catalysts for Synthesis Gas Conversion to Alcohols: Catalysts, Mechanisms and Kinetics

Abstract: Recent literature on synthesis gas conversion to higher alcohols over Mo-based catalysts is reviewed. Density functional theory calculations show that Mo-CO adsorption is weakened by C, P, or S lig...