Abstract
The hydrogenation of crotonaldehyde over Cu/Al2O3 which was modified by formic acid or acetic acid adsorption has been investigated, exposed Cu sites being characterised using infrared spectroscopy with CO as a probe molecule. Formic acid adsorption on reduced Cu0 sites generated adsorbed bidentate formate which blocked CO adsorption at many sites, induced cationic character at the remaining available sites, and partially poisoned hydrogenation reactions. Modification of the surface poisoned CO hydrogenation more than CC hydrogenation and hence promoted butanal as the dominant hydrogenation product. Desorption of formate by “ flashing” at high temperature resulted in a partly reconstructed surface which gave higher catalytic activities than an unmodified surface before formic acid treatment. However, crotyl alcohol remained a minor product. The effects of acetic acid adsorption were similar to those for formic acid except that attempts at desorption of the modifier resulted in carbonaceous residues which partially poisoned both CO adsorption and catalytic activity.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
