TY - JOUR
T1 - Effect of Lewis basicity on the continuous gas phase condensation of benzaldehyde with acetophenone over MgO
AU - Pischetola, Chiara
AU - Hesse, Fabian
AU - Bos, Jan-Willem G.
AU - Cardenas-Lizana, Fernando
N1 - Funding: The authors acknowledge the Engineering and Physical Sciences Research Council, Heriot-Watt University, and CRITICAT Centre for Doctoral Training for financial support [Ph.D. studentship to Chiara Pischetola and Fabian Hesse; Grant EP/L016419/1].
PY - 2021/8/5
Y1 - 2021/8/5
N2 - We have investigated the effect of Lewis basicity in the continuous gas phase condensation of acetophenone + benzaldehyde over MgO. The catalysts were prepared by ammonia precipitation, hydration and calcination to generate MgO with modified Lewis basicity (from CO2-TPD), dXRD (4-20 nm) and specific surface area (SSA = 58 246 m2 g-1); a direct correlation between SSA and Lewis basicity is presented. The introduction of Li+ and Cs+ served to decrease SSA and increase dXRD and Lewis basicity, linked to diffusion of the cations within the crystal structure (confirmed by XRD/STEM-EDX). All MgO systems delivered the exclusive and time invariant formation of target benzylideneacetophenone. Benzylideneacetophenone production rate is sensitive to the specific (per m2) Lewis basicity. The Cs10MgO_H(773) catalyst delivered the highest rate, attributed to high density of (Lewis basic) -O2- sites involved in the rate-determining step. Our results establish the feasibility of continuous chalcone synthesis using MgO catalysts with controlled Lewis basicity.
AB - We have investigated the effect of Lewis basicity in the continuous gas phase condensation of acetophenone + benzaldehyde over MgO. The catalysts were prepared by ammonia precipitation, hydration and calcination to generate MgO with modified Lewis basicity (from CO2-TPD), dXRD (4-20 nm) and specific surface area (SSA = 58 246 m2 g-1); a direct correlation between SSA and Lewis basicity is presented. The introduction of Li+ and Cs+ served to decrease SSA and increase dXRD and Lewis basicity, linked to diffusion of the cations within the crystal structure (confirmed by XRD/STEM-EDX). All MgO systems delivered the exclusive and time invariant formation of target benzylideneacetophenone. Benzylideneacetophenone production rate is sensitive to the specific (per m2) Lewis basicity. The Cs10MgO_H(773) catalyst delivered the highest rate, attributed to high density of (Lewis basic) -O2- sites involved in the rate-determining step. Our results establish the feasibility of continuous chalcone synthesis using MgO catalysts with controlled Lewis basicity.
KW - Benzaldehyde and acetophenone
KW - Benzylideneacetophenone
KW - Li-and Cs-promotion
KW - MgO
KW - Selective gas phase condensation
KW - Surface basicity
U2 - 10.1016/j.apcata.2021.118277
DO - 10.1016/j.apcata.2021.118277
M3 - Article
SN - 0926-860X
VL - 623
JO - Applied Catalysis. A, General
JF - Applied Catalysis. A, General
M1 - 118277
ER -