I know it - I like it - I buy it! The role of knowledge for the adoption of battery-electric and hydrogen vehicles

Although research in different disciplines has demonstrated that education and information can lead to more sustainable attitudes and related behaviour, supporting the assumptions of Roger's Diffusion of Innovation Theory, other research points to a knowledge-behaviour gap. Thus, we shed light on the question of whether knowledge can help to accelerate the adoption of transport innovations and under which conditions. Specifically, this research paper extends the current findings regarding the knowledge-attitude-behaviour process in the adoption of electric vehicles (EVs) by focusing on different types of knowledge and including the adoption of hydrogen-powered fuel-cell electric vehicles (FCEVs). We present two empirical studies from Germany - one on the adoption of electric vehicles by employees (n = 1,174) assessing potential differences in subjective and objective knowledge and one on the adoption of EVs and FCEVs in the general population (n = 1,344) assessing differences in knowledge regarding the innovation's diffusion phase. Using mediation analyses, the results of both studies support the theoretical assumption and the expected process: Knowledge has a positive impact on the adoption intention of EVs and FCEVs; this effect is mediated by individuals' attitudes toward the technological innovation. Regardless of the innovation's diffusion phase, greater knowledge leads to a more positive attitude towards the innovation, and a more positive attitude leads to a higher adoption intention of the technological innovations. The effect appears stable: It remains for subjective and objective knowledge (Study 1), for different measures of adoption intention (Study 1 and Study 2) as well as for different technological innovations in the transport sector which are in different diffusion phases (Study 2). Details of the results, their impact for implementing new technologies in other areas as well as the role of the media will be discussed.