Catalytic role and location of Cs promoter in Cs–Au/TiO2 catalysts for propanol synthesis from CO2, C2H4 and H2

Alcohol Synthesis from CO2, H2, and Olefins over Alkali‐Promoted Au Catalysts—A Catalytic and In situ FTIR Spectroscopic Study

“…To compare the catalystp erformance in both reactions (propanol and butanol synthesis) tests with CO 2 /H 2 /C 2 H 4 /N 2 were also performed at 8bar.B efore performing steady-state catalytic tests as pecial activation procedure was applied, [19] the specific effect of which on the catalystp roperties has been discussed later in the manuscript. To compare the catalystp erformance in both reactions (propanol and butanol synthesis) tests with CO 2 /H 2 /C 2 H 4 /N 2 were also performed at 8bar.B efore performing steady-state catalytic tests as pecial activation procedure was applied, [19] the specific effect of which on the catalystp roperties has been discussed later in the manuscript.…”

“…In previous studies [19] it was found that aspecial activationprocedurei sn ecessaryt oa chieveh igh selectivity for propanol. Duringt his activation process the catalysts were exposed to a specialf eed (CO 2 /H 2 /C 2 H 4 /N 2 = 4:2:1:1) at 250 8Cf or 16 hb efore the steady-state catalytic tests were performed.…”

“…Thus, after comprehensive testing of several metals and supports, gold nanoparticles (Au NPs) supported on TiO 2 (anatase, rutile) or SiO 2 and doped with alkali metals (K, Cs) have been proven to catalyze all these reactions at temperatures between 200-250 8Ca nd pressure of 20 bar. [21] As these studies [17][18][19][20][21] focused on particular aspects for as elected catalysts ystem, ac omprehensive study is neededt o elucidatet he specific functiono ft he different alkali dopants and the different support materials in the alcohol synthesis reaction from CO 2 ,H 2 ,a nd C 2 H 4 .F urthermore, it is not clear if this approach has general relevance thati s, if it is also applicable for the synthesis of butanol from CO 2 ,H 2 ,and C 3 H 6 . This is caused by an enhanced ability of the TiO 2 -based catalysts for CO 2 activation, as concluded from in situ fourier-transform infrared (FTIR) spectroscopy and temporal analysiso fp roducts (TAP) studies.…”

“…[9][10][11][12][13] Higher alcohols are synthesized by catalytic homologation of methanol or directly from CO 2 and alkenes in homogeneously catalyzed reactions. [17][18][19][20][21][22] Finding multifunctional catalysts for this reaction is challenging because the RWGS reaction runs above 300 8Co wing to thermodynamic constraints, but hydroformylationr equires lower temperatures. [17][18][19][20][21][22] Finding multifunctional catalysts for this reaction is challenging because the RWGS reaction runs above 300 8Co wing to thermodynamic constraints, but hydroformylationr equires lower temperatures.…”

“…[17][18][19][20][21][22] Finding multifunctional catalysts for this reaction is challenging because the RWGS reaction runs above 300 8Co wing to thermodynamic constraints, but hydroformylationr equires lower temperatures. [19] Comparing the performance of K-promoted catalysts, the SiO 2 -based catalysts showed higherC O 2 conversionst han their TiO 2 -based counterparts, whereas the undesired hydrogenationo fe thene was found to decrease with increasingKloading. [22] The performance of these catalysts was found to be influenced by the nature and loading of alkali dopanto nb oth supports but in ad ifferent way.C oncerning the role of the Cs pro-Au/TiO 2 and Au/SiO 2 catalysts containing 2wt% Au and different amounts of Ko rC sw ere tested for alcohol synthesis from CO 2 ,H 2 ,a nd C 2 H 4 /C 3 H 6 .1 -Propanol or 1-butanol/isobutanol were obtained in the presenceo fC 2 H 4 or C 3 H 6 .H igher yields of the corresponding alcohols were obtained over TiO 2 -based catalysts in comparison with their SiO 2 -based counterparts.…”