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

Abstract 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 (CuWO4) 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 CuWO4 foams were prepared by a continuous sintering approach. The obtained CuWO4 catalysis inherited the porous structure from the copper foam and had a high loading density of CuWO4 crystal particles. Afterwards, DMSO oxidation was employed as a probe reaction to explore the catalytic performance of CuWO4 foam. Significant findings CuWO4 foam showed prefect catalytic activity in a scale-up microreactor. The average crystallite size of CuWO4 were increased from 52.8 to 57.7 nm with extension of sintering time. Under the optimum condition (residence time was 40 min, CuWO4 catalyst was CuWO4F-5 and reaction temperature was 80 oC), 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 CuWO4 foam are conducive to enhancing the catalytic performance of CuWO4 foam. This research indicates the potential opportunity to apply CuWO4 foam in a scale-up microreactor.