Recently, hydrogen energy has been increasingly considered for decarbonization, and it could drive technological convergence in diverse areas. This study examines technological convergence in hydrogen energy and analyzes how technological characteristics are associated with survival using triadic patent data. FP-growth, an association rule mining technique, identifies convergent patterns of hydrogen energy technology. Then, a causal survival forest model is applied to estimate heterogeneous treatment effects on technological survival, measured as the life span of forward citations. The results indicate that breakthrough patents do not exhibit a statistically significant survival advantage, and science linkage measured through non-patent literature citations also shows no significant average effect. Instead, survival heterogeneity is largely associated with structural technological attributes of patents. In particular, claims, generality, and originality emerge as important moderators shaping how treatment effects vary across technological contexts. These findings suggest that the sustainability of hydrogen energy technologies depends less on breakthrough designation or science linkage than on the structural robustness and technological scope of inventions. The study provides policy implications for advancing hydrogen technology through strategies that broaden the scope of invention and strengthen technological robustness.
Won Suk Lee (Thu,) studied this question.