Fatty acids and their derivatives can be converted to renewable and carbon‐neutral fuel‐like hydrocarbons that are entirely fungible with fossil fuels. Typically, these hydrocarbon‐based biofuels are obtained through hydrotreating, a method which has the significant disadvantages of requiring problematic sulfided catalysts and high pressures of hydrogen. In recent years, decarboxylation/decarbonylation has been proposed as an alternative method, as this approach has the advantages of permitting the use of simpler catalysts and requiring less hydrogen than hydrotreating. In this contribution, the deoxygenation of fatty acids and their derivatives to fuel‐like hydrocarbons via decarboxylation/decarbonylation is critically reviewed. The main aspects discussed include the influence of the feed, catalyst, reactor system and reaction conditions on the decarboxylation/decarbonylation reaction, as well as the reaction mechanism and catalyst deactivation/regeneration. Copyright © 2012 Society of Chemical Industry

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The deoxygenation of triglycerides (tristearin, triolein and soybean oil) under nitrogen atmosphere was investigated over 20 wt% Ni/C, 5 wt% Pd/C and 1 wt% Pt/C catalysts. Use of the Ni catalyst resulted in near quantitative conversion of the triglyceride in each case, high yields of linear C5 to C17 alkanes and alkenes being obtained. Oxygen was rejected as CO and CO 2 , while small amounts of light alkanes (C1-C4) and H 2 were also formed. 13 C NMR spectroscopic analysis of the liquid product from soybean oil deoxygenation at intermediate reaction times suggested that one pathway for triglyceride deoxygenation involves liberation of fatty acids via C-O bond scission and concomitant H transfer, followed by elimination of CO 2 from the acids in a later step. Compared to Ni, catalysts containing Pd or Pt supported on activated carbon showed lower activity for both triglyceride deoxygenation and for cracking of the fatty acid chains.

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NOx storage on Pt/Al 2 O 3 and Pt/La-Al 2 O 3 in the temperature range 80-160 ºC was investigated by means of microreactor and in situ DRIFTS experiments, to ascertain their suitability for

H magnetic-angle spinning (MAS) NMR measurements have been performed on a number of crystalline titanias, and on amorphous silica-supported titania and titania-silica, with the aim of measuring the characteristic proton chemical shifts of hydroxy groups bound to titanias of different crystalline form. In the case of anatase, signals observed at 6 = 2.3 and 6.7 ppm correspond to terminal and bridging hydroxy groups, the results of deuterium exchange experiments (using D,O) and IR data supporting these assignments. For rutile, signals observed at 6 = 2.2 and 5.3 ppm are similarly assigned. Hydroxy groups bound to amorphous titania supported on silica (containing tetrahedrally coordinated Ti") are found to possess a characteristic chemical shift of 6 = 3.3 ppm. Deconvolution of 'H NMR spectra of titania-silica (containing 8 wt.% Ti) indicate the presence of a signal at 6 3.3 ppm, which is similarly assigned to hydroxy groups bound to tetrahedrally coordinated Ti", together with signals assigned to anatase and silanol groups. These observations are consistent with literature reports indicating the presence of two main titania phases in titania-silicas : an amorphous phase containing isolated Ti sites tetrahedrally coordinated by Si-0 and OH groups, and segregated nanodomains of TiO, (anatase or rutile).

Although manganese oxide (MnO2) exhibits excellent activity in various oxidation reactions, especially for volatile organic compound oxidation, the origin of the catalytic activity remains ambiguous and controversial. In this study, four types of MnO2 catalysts with crystal phases corresponding to α-, β-, γ-, and δ-MnO2 were synthesized, and their catalytic properties in HCHO and C6H6 oxidation were studied. α- and γ-MnO2 were found to possess much better activity for C6H6 oxidation than δ- and β-MnO2 catalysts, whereas δ-MnO2 exhibited the best performance for HCHO oxidation as compared with other types of MnO2. Three kinds of oxygen species were discriminated based on their Mn–O bond strength and reducibility. By quantitatively correlating the amount of specific oxygen species with the reaction rates, the catalytic roles of different oxygen species in HCHO and C6H6 oxidation were clarified. With the assistance of isotopic labeling studies, the participation of oxygen species in C6H6 oxidationwhich followed a Mars–van Krevelen mechanismwas illuminated.