Does a sulfur-resistant shift catalyst require temperature elevation for reduction? Or direct vulcanization?
Thread Content
Does a sulfur-resistant shift catalyst require temperature elevation for reduction? Or direct vulcanization?
It should be to raise the temperature first and then carry out vulcanization; there is no such thing as reduction
Weren’t reducing agents in the past always reduced from their oxidized state by heating before being used again? The sulfur-resistant material undergoes direct sulfidation upon heating, waiting for the shift gas – is that right?
CoO + H2S = CoS + H2O + 13.4 KJ/mol; MoO3 + 2H2S + H2 = MoS2 + 3H2O + 48.1 KJ/mol. Direct sulfidation occurs, but a certain activation temperature is required for this process, around 230 degrees℃
In the past, the active form of iron-based catalysts was elemental iron; whereas the active form of sulfur-resistant shift catalysts used today is cobalt sulfide and molybdenum sulfide. Since their states are different, reduction was required in the past, while sulfidation is needed now.