Cobalt carbide from Co-Mn layered double hydroxide: highly efficient catalyst for toluene pyrolysis

The cobalt carbide (Co2C) innovatively prepared from Co-Mn layered double hydroxide (CoMn LDH) has been investigated and evaluated toward its alternative synthesis conditions and different catalytic performances. Along with various characterization techniques, the preparation basically contains four steps (synthesis of CoMn LDH, calcination, reduction and crystallization) that transforms CoMn LDH to CoMn spinel, then to Co2C. Catalyst evaluation toward toluene pyrolysis was conducted. The sample with Co2C exhibited almost 100 % conversion rate of toluene, where the resulting hydrogen yield (~ 1.8 %) is 6 times more than that of the blank test by using silica sand (~ 0.3 %), realizing the full transfer of hydrogen element from toluene to hydrogen molecule. Furthermore, based on the textural analysis and DFT-D calculation, which theoretically explained the easy accessibility of toluene to the crystal surface of Co2C (001) with a relatively high adsorption energy (about −280 kJ mol−1), it suggested that Co2C...