Recyclable Pd ionic catalyst coated on cordierite monolith for high TOF Heck coupling reaction

Abstract

$$\hbox {Pd}^{2+}$$ ionic catalyst, $$\hbox {Ti}_{0.97} \hbox {Pd}_{0.03} \hbox {O}_{1.97}$$ was coated over cordierite monolith by solution combustion method. The catalyst coated on the cordierite is nano-crystalline as seen from XRD studies. Coated catalyst was used for Heck coupling reactions with different substrates of aryl halides and olefins. Thus handling nano-crystalline catalyst powder is avoided by fixing it on a solid catalyst cartridge. Heck coupled products were characterized using $$^{1}\hbox {H}$$ NMR, $$^{13}\hbox {C}$$ NMR, Mass and FTIR spectroscopy. This catalyst showed high selectivity towards Heck coupling reaction. Turnover frequencies (TOF) for each of the reactions were found to be very high. The catalyst was recycled up to 7 times with total TOF 3017 $$\hbox {h}^{-1}$$ , which is found to be a new green technique in the Heck coupling reaction. $$\hbox {Ti}_{0.97} \hbox {Pd}_{0.03} \hbox {O}_{1.97}$$ catalyst is coated on cordierite monolith honeycomb (HC) by solution combustion method and it is used in the Heck coupling reaction. Reactions are done in a specially designed flask. Catalyst is recycled for 7 times. The total turnover frequency (TOF) after 7 cycles was 3017 $$\hbox {h}^{-1}$$ .