Preparation of CuWO4 foam and its use as a heterogeneous catalyst for dimethyl sulfoxide oxidation in a scale-up microreactor

Background Metal foam has been demonstrated numerous advantages in fine chemistry when used as catalyst support. In this research, a novel strategy for the fabrication of copper tungstate (CuWO 4 ) foam as heterogeneous catalysis to conduct dimethyl sulfoxide (DMSO) oxidation reaction in a scale-up microreactor was proposed. Methods A series of three-dimensional skeleton CuWO 4 foams were prepared by a continuous sintering approach. The obtained CuWO 4 catalysis inherited the porous structure from the copper foam and had a high loading density of CuWO 4 crystal particles. Afterwards, DMSO oxidation was employed as a probe reaction to explore the catalytic performance of CuWO 4 foam. Significant findings CuWO 4 foam showed prefect catalytic activity in a scale-up microreactor. The average crystallite size of CuWO 4 were increased from 52.8 to 57.7 nm with extension of sintering time. Under the optimum condition (residence time was 40 min, CuWO 4 catalyst was CuWO 4 F-5 and reaction temperature was 80  o C), a high dimethyl sulfone yield of 65.4% was obtained. The yield of MSM reached nearly 65.3% in the run time of 1 h and showed a value of 50.4% even in the run time of 4 h. Higher reaction contact surface and larger crystal particles of CuWO 4 foam are conducive to enhancing the catalytic performance of CuWO 4 foam. This research indicates the potential opportunity to apply CuWO 4 foam in a scale-up microreactor.