Granule of potassium hexatitanate fine crystals for photocatalytic steam reforming of methane

Photocatalytic steam reforming of methane (PSRM) can produce hydrogen from methane even at room temperature and thus has been studied recently. In the present study, to know the structural aspects affecting the photocatalytic performance, many fine rod-like crystals of potassium hexatitanate (K2Ti6O13, KTO) were synthesized by a flux method with varying the preparation conditions and examined their photocatalytic activities for the PSRM after loading Rh cocatalyst. It was found that a Rh/KTO fine crystal photocatalyst with a larger surface area exhibited the highest hydrogen production rate (up to 30 μmol h−1) with high selectivity. Further, the granulated crystals exhibited 2.1–2.6 times higher hydrogen production rate than the original powdery fine crystals, suggesting that the physical contact between the fine crystals contributes to the interparticle transfer of the photoexcited carriers and thus it enhances the photocatalytic activity.