Decarboxylation of Diunsaturated Linoleic Acid to Heptadecane over Zeolite Supported Pt/ZIF-67 Catalysts

Abstract

Diunsaturated linoleic acid was deoxygenated in H 2 , CO 2 , and N 2 atmospheres over 0.3 wt % Pt/ZIF-67/ Zeolite 5A bead catalysts. Nearly complete conversion was observed in H 2 and N 2 atmospheres (≥95%). When N 2 and CO 2 were employed during the reaction, the primary reaction pathway was decarboxylation. In the case of H 2 , the formation of octadecane in the liquid product suggests that hydrodeoxygenation is a competing pathway to decarboxylation. Yields to heptadecane under H 2 , CO 2 , and N 2 were 65.3, 63.5%, and 58.4%, respectively. The best catalyst recyclability was observed in CO 2 atmospheres where activity decreased only ∼1% on regeneration. Activity losses were higher in nitrogen and hydrogen, 3.8 and 10.7%, respectively. An investigation of esters in the reactants and products led to an alternative method for the evaluation of total conversion (% deoxygenation). Strong correlations between titrimetric assays and ATR-FTIR were observed.

Deoxygenation of Stearic Acid over Cobalt-Based NaX Zeolite Catalysts

“…Aspects of interest in the valorization of fatty acids include (i) one pot continuous conversion of both saturated and unsaturated fatty acids; (ii) employing non-noble metals for cheaper catalysts; and (iii) decreasing the cost of reaction conditions by lowering temperature/pressure and eliminating hydrogen [6]. With respect to (i), it has been shown that a higher degree of unsaturation in the feedstock results in lower conversion and selectivity [7][8][9]. Regarding (ii), lower selectivities to alkanes have been shown when removing Pt or Pd from the catalyst [10,11].…”

Development of Bifunctional Hydrodeoxygenation Catalyst Rh‐HY for the Generation of Biomass‐Derived High‐Energy‐Density Fuels

“…Many parallel efforts are currently underway to reduce the use of petroleum as a source of fuels and fine chemicals. Among the potential fossil fuel alternatives, lignocellulosic biomass is considered a promising renewable carbon feedstock replacement for crude oil to produce engine fuels, commodity chemicals, solvents, pharmaceuticals, and agrochemicals . This type of biomass is composed of polysaccharides (cellulose and hemicellulose) and lignin, a polymer containing mainly aromatic moieties.…”

“…Among the potential fossil fuel alternatives, lignocellulosic biomass is considered a promising renewable carbon feedstock replacement for crude oil to produce engine fuels, commodity chemicals, solvents, pharmaceuticals, and agrochemicals. [1][2][3][4] This type of biomass is composed of polysaccharides (cellulose and hemicellulose) and lignin, a polymer containing mainly aromatic moieties. Most research efforts to date have focused on developing catalytic treatments for cellulose-derived fractions, while the research on new processes using ligninderived fractions has received less attention.…”

Decarboxylation of stearic acid over Ni/MOR catalysts

“…Unfortunately, sulfided catalysts have poor stability in the presence of water, which is largely unavoidable in biomass feedstocks, and noble metal catalysts are extremely expensive . Therefore, low noble metal loadings were explored under similar conditions, yielding promising results . Simultaneously, researchers began to study the effect of different gas atmospheres, seeking to remove hydrogen from the reaction, proposing decarboxylation (DCO) as an alternative pathway .…”

“…The use of zeolites as catalytic supports for deoxygenation of fatty acids has been explored by our group and independent research groups and has yielded promising results as a bifunctional catalyst support providing enhanced metal dispersion, higher catalytic conversion and improved stability . In the current study, zeolite mordenite (MOR) was selected as the catalytic support material for Ni due to its robust catalytic properties in industrial settings, high surface areas, and tunable acidity .…”