The nexus between technological innovation capabilities and carbon mitigation in firms: moderating roles of external and internal innovation pathways

China is embracing innovative strategies to reduce carbon emissions (CEs) and promote environmental sustainability. We contribute to existing studies on the relationship between technological innovation capabilities (TICs) and CEs by establishing a systematic analysis framework linked to corporate innovation pathways. It encompasses the external innovation pathways associated with domestic cooperation patterns and foreign technology absorption, as well as internal innovation pathways associated with Research & Development (R&D) input. Based on the cross-referencing patent information datasets of Chinese industrial listed firms from 2010 to 2021, we examine how TICs impact firms’ CEs and the moderating mechanisms of different external and internal innovation paths. The results show that firms’ TICs significantly reduce the level of CEs. Moreover, domestic collaboration with other firms or research organizations fails to motivate the carbon reduction effect of TICs significantly, while the assimilation of foreign technologies effectively enhances the effect of TICs on carbon reduction. The carbon-reducing effect of TICs is also bolstered when firms’ R&D expenditure intensity and personnel intensity exceed the certain threshold values of 0.0833 and 0.1413, respectively. These findings provide new policy insights for industrial enterprises to leverage technological innovation to reduce CEs through various innovation pathways.