Direct ink writing of 3D SiC scaffold as catalyst support for thermally autonomous methanol steam reforming microreactor

Methanol steam reforming (MSR) has been proven to be a feasible approach for in-situ hydrogen production. This paper designed a novel thermally autonomous MSR microreactor with regular-shaped pores SiC scaffold as catalyst support. The SiC scaffolds with four different pore sizes were fabricated by direct ink writing (DIW) of polycarbosilane-based solution. After post processing, the printed ceramic precursor scaffolds shrank homogeneously and converted into porous SiC ceramic, which maintain original regular-shaped pores. The experimental results showed that the microreactor with smaller pore-sized SiC scaffold catalyst support had the highest hydrogen production value while poor characteristics in fluid flow. At an inlet flow rate of 60 μl/min and reaction temperature of 280 °C, the microreactor with 0.5 mm pore-sized SiC scaffold can produce the average hydrogen of 53.85 ml/min with methanol conversion of 82.88%. After 24 h of continuous operation, the SiC scaffold still had great hydrogen production, demonstrating remarkable stability as catalyst support for MSR hydrogen production system. This work demonstrates that ceramic scaffold catalyst support fabricated by DIW is a promising method for the development of MSR microreactors for regulation of the fluid flow and hydrogen production performances.