Journal
SURFACE SCIENCE
Volume 646, Issue -, Pages 170-178Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.susc.2015.07.011
Keywords
Solid base; In-situ XPS; Nanoparticulate MgO; Methanol; Ester; Biodiesel synthesis
Categories
Funding
- EPSRC [EP/F063423/1, EP/K000616/1, EP/G007594/4]
- Royal Society [IF100206]
- Royal Society [IF100206] Funding Source: Royal Society
- Engineering and Physical Sciences Research Council [EP/G007594/2, EP/F063423/2, EP/F063423/1, EP/K000616/1, EP/G007594/4] Funding Source: researchfish
- EPSRC [EP/F063423/1, EP/G007594/4, EP/K000616/1, EP/G007594/2, EP/F063423/2] Funding Source: UKRI
Ask authors/readers for more resources
An in situ XPS study of water, methanol and methyl acetate adsorption over as-synthesised and calcined MgO nanocatalysts is reported with a view to gaining insight into the surface adsorption of key components relevant to fatty acid methyl esters (biodiesel) production during the transesterification of triglycerides with methanol. High temperature calcined NanoMgO-700 adsorbed all three species more readily than the parent material due to the higher density of electron-rich (111) and (110) facets exposed over the larger crystallites. Water and methanol chemisorb over the NanoMgO-700 through the conversion of surface O2- sites to OH- and coincident creation of Mg-OH or Mg-OCH3 moieties respectively. A model is proposed in which the dissociative chemisorption of methanol occurs preferentially over defect and edge sites of NanoMgO-700, with higher methanol coverages resulting in physisorption over weakly basic (100) facets. Methyl acetate undergoes more complex surface chemistry over NanoMgO-700, with C-H dissociation and ester cleavage forming surface hydroxyl and acetate species even at extremely low coverages, indicative of preferential adsorption at defects. Comparison of C 1s spectra with spent catalysts from tributyrin transesterification suggest that ester hydrolysis plays a key factor in the deactivation of MgO catalysts for biodiesel production. (C) 2015 Published by Elsevier B.V.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available