Amid the intensifying global discourse on sustainability, both governments and corporations are increasingly committed to advancing sustainable development and promoting environmentally responsible consumption. Yet, despite consumers’ growing environmental consciousness, the psychological mechanisms that shape green purchase intentions remain insufficiently understood. Taking the perspective of the Elaboration Likelihood Model (ELM), this study investigates the effects of message framing (positive vs. negative) and Word-of-Mouth (WOM) communication on green purchase intention, emphasizing the mediating roles of perceived risk and perceived quality and the moderating influence of product type (search vs. experience goods). Employing a 2 (message framing) × 2 (product type) between-subjects experimental design, data were collected from 381 participants and analyzed using structural path modeling. The findings reveal that message framing exerts no direct influence on green purchase intention but operates indirectly through perceived risk and perceived quality. In contrast, positive WOM demonstrates both direct and indirect positive effects on green purchase intention. Furthermore, product type significantly moderates these relationships: negative framing heightens perceived risk for experience goods, whereas positive framing enhances perceived quality for search goods. These results underscore the pivotal role of cognitive appraisals in mediating the effects of marketing communication on green purchasing intentions and advance theoretical understanding of how framing and interpersonal influence interact with product characteristics to shape sustainable consumer decision-making.