3.3. General Procedure for Catalyst Recycling

The catalyst recovered after the filtration of the crude reaction mixture was washed with water (20 mL), acetone (20 mL), and methanol (20 mL), dried under vacuum at room temperature overnight and room temperature, and reused in the next runs under the same optimized reaction conditions. The conversions obtained after the recycling tests were measured by GC-MS. Catalyst structure and Pd loading were also analyzed after recycling.

The total Pd content was determined using ICP–OES with a Perkin Elmer Optima 7000 (Perkin Elmer, Norwalk, CT, USA) spectrometer via standard addition.