Abstract
The sulfur–iodine thermochemical water-splitting cycle is a promising route proposed for hydrogen production. The decomposition temperature remains a challenge in the process. Catalysts, such as Pd supported on Al2O3, are being considered to decrease reaction temperatures. However, little is known regarding the kinetic behavior of such systems. In this work, zinc sulfate thermal decomposition was studied through non-isothermal thermogravimetric analysis to understand the effect of a catalyst within the sulfur–iodine reaction system context. The findings of this analysis were also related to a thermodynamic assessment. It was observed that the presence of Pd/Al2O3 modified the reaction mechanism, possibly with some intermediate reactions that were suppressed or remarkably accelerated. The proposed model suggests that zinc sulfate transformation occurred in two sequential stages without the Pd-based material. Activation energy values of 238 and 368 kJ·mol−1 were calculated. In the presence of Pd/Al2O3, an activation energy value of 204 kJ·mol−1 was calculated, which is lower than observed previously.
Highlights
Over the last few decades, the question regarding how energy systems must be updated to reduce carbon emissions and to lower their contribution to climate change has become increasingly urgent
Kurban [42], which was applied in this study to perform a kinetic modeling assessment of ZnSO4 thermal decomposition in the presence and absence of a Pd/Al 2O3 catalyst
The achieved results suggest that the thermal decomposition of monohydrate zinc sulfate under an inert atmosphere (N2 ) first proceeds through hydration water removal
Summary
Over the last few decades, the question regarding how energy systems must be updated to reduce carbon emissions and to lower their contribution to climate change has become increasingly urgent. This can be observed in reports issued by international agencies, such as the United Nations [1], and studies on the affordability and security of these future systems, as published by Sencar et al [2]. In this context, hydrogen presents itself as a potential cleaner fuel compared to carbon-based fossil fuels, as only water results from H2 combustion. Not all methods are based on renewable sources, and the most relevant alternatives explored so far are based on methane decomposition [12,13] or thermochemical water-splitting cycles [14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
