*2.3.3 BET surface area analysis*

BET surface area analyser (Nova-Quantachrome 4200 e) was used to measure the surface area of all the catalysts. The measurement was done by using N2 as probe molecule at liquid nitrogen temperature (−190°C). Before the measurement, all the catalysts were degassed at 300°C at the pressure of 10<sup>−</sup><sup>5</sup> Torr for 6 h. Linear portion of the BET plots was used for the determination of BET surface area.
