“…The palladium levels in the products were lower in these systems than in homogeneous systems, but the catalytic activities decrease gradually in the recycled systems. This might be because of weak coordination between palladium and the ligands, leading to palladium leaching (Mahdavi, Zirakzadeh, & Amani, 2007;Pathan & Patel, 2012;Zhao, Murakami, Shirai, & Arai, 2000), or failure to provide a hydrophobic microenvironment for the active sites of the catalyst (Du et al, 2004).…”