Abstract
A series of pincer ligands, LA to LD were synthesized and characterized using nuclear magnetic resonance spectroscopy, infrared spectroscopy, high-resolution electrospray ionisation mass spectrometry and elemental analysis. Complexation reactions of these ligands with [PdCl2(MeCN)2] gave the corresponding tridentate N^N^N Pd(II) complexes (Pd-LA to Pd-LD). These molecular complexes were characterized using NMR, FTIR, TGA, elemental analysis and high-resolution electrospray ionisation mass spectrometry. Complex Pd-LA and Pd-LD were immobilized on SBA-15 and characterized using TEM, SEM, TGA, FTIR and pXRD. Both molecular and supported Pd(II) complexes were evaluated as catalysts in the hydrodeoxygenation of δ-furfurylidenelevulinic acid (C10) using molecular hydrogen as a hydrogen source. The catalytic products were characterized via GC-FID. The Pd(II) catalysts showed average activity and selectivity towards the formation of n-decane. Pd-LA, Pd-LB, Pd-LC, Pd-LD, Pd-LA/SBA-15 and Pd-LD/SBA-15 also formed a second product (4-oxodecanoic acid) in significant amounts. Pd-LA and Pd-LA/SBA-15 achieved the highest conversions of C10. Pd-LA/SBA-15 showed significant catalytic activity up to three cycles.