Eco-friendly catalytic converter from rice husk: optimised copper coating to cut emissions

In this study, a catalytic converter was developed using activated carbon derived from rice husks coated with copper using a screen-printing method. Rice husks were chosen because they have high cellulose, lignin, and silica contents. These contents provide favourable characteristics for producing activated carbon. The fabrication process was carried out by pre-carbonisation at 400 °C for 2 h. Subsequently, chemical activation was performed using a mixture of HCl, H₃PO₄, and NaOH. The next step was carbonisation at 650 °C for 12 h. The resulting activated carbon was characterised by XRD, FTIR, and SEM-EDS analyses to evaluate the crystal structure, functional groups, and pore morphology. The catalytic converter coated with a 250 µm copper layer showed the best performance, with a reduction in HC emissions from 674 ppm to 173 ppm and CO emissions from 2.84% to 1.68%. The engine performance improved, as indicated by the increased torque and power, and noise reduction of 7.5%, 9%, and 4.7%, respectively. These results indicate that the developed catalytic converter is an efficient, low-cost, and environmentally friendly solution for reducing vehicle emissions.