Societal decarbonization is essential for environmental sustainability and prosperity, requiring cohesive efforts to advance materials circularity alongside the development of zero-carbon energy and heat solutions. In most systems, these challenges are addressed separately. However, creating integrated solutions that connect opportunities across energy and materials loops can be transformative and critical for achieving lasting impact. This work shows the innovative use of mixed polyolefin wastes for electrification of heating to enable industrial decarbonization. We demonstrate the conversion of mixed polyolefin wastes into structured carbon with exceptional Joule heating properties using fused filament fabrication (FFF) printing, crosslinking, and pyrolysis. This waste-derived carbon serves as both a catalyst support and heating element for electrified hydrogen production