Reactivity and stability of supported Pd nanoparticles during the liquid-phase and gas-phase decarbonylation of heptanoic acid

- Decarbonylation was the primary reaction of heptanoic acid catalyzed by Pd at 573 K.
- Liquid heptanoic acid at 573 K caused severe sintering of carbon-supported Pd nanoparticles.
- Sintering of carbon-supported Pd was minimal with dilute liquid acid or gaseous acid at 573 K.
- Silica-supported Pd nanoparticles were stable in both liquid- and gas-phase reactions.
- In addition to Pd sintering, deposition of carbon species was responsible for the deactivation of the catalyst.