Mg and Al mixed oxides and the synthesis of n-butanol from ethanol

Review of catalytic systems and thermodynamics for the Guerbet condensation reaction and challenges for biomass valorization

“…Studies of Guerbet condensation with catalysts having acid-base bifunctionality show that dehydration rates are higher on more acidic materials, whereas dehydrogenation is favorable over basic sites. The effect is clearly visible when materials with tunable acid-base functionality are used, such as Mg/Al mixed oxides, 72,95,115 hydroxyapatites, 121 Mg/Zr mixed oxides 103 and Na-doped ZrO 2 . 69 Materials containing more and stronger acid sites facilitate undesirable dehydration reactions.…”

“…Many publications focus on the Guerbet selfcondensation of ethanol for the production of n-butanol and higher alcohols. [65][66][67][68][69][70][71][72][73][74][75][76][77][78] Just like ethanol, n-butanol can be used as a renewable fuel, yet in comparison with ethanol, it has a higher energy density, a lower volatility and a lower propensity to absorb water. Methanol on the other hand lacks a second carbon atom and cannot self-condensate by Guerbet condensation.…”

Recent advances on the utilization of layered double hydroxides (LDHs) and related heterogeneous catalysts in a lignocellulosic-feedstock biorefinery scheme

“…A study of Mg and Al mixed oxides showed that adjacent acid and medium basic sites are needed in order to generate the intermediate compounds. 57 These acid-base pairs can be In terms of the selectivity towards 1-butanol, the investigated metals can be ranked as follows: Ni > Pt > Au ∼ Rh > Ru ≫ Ag. CuMgAlO x mixed metal oxides with Cu contents between 4 and 38 at.% prepared by the thermal decomposition of layered double hydroxides have been used for the vapor phase coupling of methanol and ethanol.…”

“…20 Additionally, the uniform distribution of the M 2+ and M 3+ cations in the layered structure makes these materials excellent precursors for the preparation of highly dispersed metal-supported catalysts. [52][53][54][55][56][57] This preparation approach requires the introduction of the catalytically active species as substituted cations in the structure of the LDHs during the synthesis, followed by calcination and reduction steps. It allows the formation of well-dispersed metal NPs on a mixed oxide matrix (MMO).…”

Role of Different Feedstocks on the Butanol Production Through Microbial and Catalytic Routes

“…It was verified that the Mg and Al mixed oxides were able to promote the synthesis of C 4 compounds from ethanol and 20-40 % of selectivity was achieved for butanol. The authors observed that the hydrogenation capacity of the catalyst as well as selectivity to n-butanol increases with increase in concentration of Mg ( Carvalho et al 2012). Riittonen et al (2012) studied one-pot liquid-phase catalytic conversion of ethanol to 1-butanol over aluminium oxide.…”