Screening and optimisation of Mo:Fe(2)/CAR catalysts in one-step
synthesis of methylal via methanol oxidation
In the one-step preparation of methylal from methanol, achieving high
methylal yield is a huge challenge. To address this problem, in this
study a new Mo:Fe(2)/CAR catalyst was designed, screened and optimised.
The results showed that the optimised bifunctional catalyst had superior
catalytic performance, and the yield of methylal could reach 81.33%,
much higher than other research results of this process. Through the use
of XPS, NH3-TPD and PY-FTIR it was found that the appearance of Mo5+
promoted the coordination of the two terminal oxygen with the Mo double
bond in the Fe2(MoO4)3 octahedron, and that the increase in the weak
acid strength of the catalyst and the coordination of suitable Brønsted
acids (B acids) and Lewis acids (L acids) was the root cause of the
catalytic activity. The apparent activation energy also further proved
that Mo:Fe(2)/ HZSM-5(80-80) was highly suitable for the one-step
production of methylal from methanol.