The objective of this work was to investigate and contrast the mechanism of different B-site dopants for catalytic activity and sulfur resistance under equivalent conditions. LaCo_1−xM_xO₃ (M = Fe, Cr, Cu) perovskite-type catalysts were synthesized by a sol–gel method, and the optimized samples were tested for toluene oxidation before and after sulfur aging. The properties of the catalysts were investigated in detail by XRD, FT-IR, N₂ adsorption–desorption, H₂-TPR, XPS and in situ DRIFTS to elucidate the inner mechanisms of the catalytic reaction and poisoning processes. The results indicated that introducing specific metal cations with a suitable ratio into the B-site of perovskite could improve the catalytic activity and weaken the negative effect of SO₂ poisoning. The reasons for the improvement of catalytic activity on different doped catalysts are similar and mainly lie in the change of reduction property, oxidation state of the B-site, and content of oxygen vacancies. However, the mechanism of sulfur resistance caused by different dopants is not identical. The introduction of different metal cations will cause certain differences in some factors such as reducibility, lattice stability, sulfur adsorption and sulfate content, thus leading to the differentiation of sulfur tolerance for doped perovskite catalysts. In this study, the optimization effect of Fe dopant is better than that of Cr and Cu dopants, illustrating that the high stability of the perovskite lattice and the insensitivity to sulfur species are the key factors for its outstanding sulfur resistance. The results provide insights into guiding the practical composition and life cycle optimization of perovskite-type catalysts in the industrial application of removing sulfur-containing VOCs.

The heat pipe (HP) is widely applied in the thermal management field at present. In order to make use of the low-grade and renewable energies to maintain building thermal comfort in the heating season, more and more studies with respect to improving the thermal performance of the building heating system integrated with the HP (BHSIHP), such as the floor heating system integrated with the HP (FHSIHP), the thermal storage wall heating system integrated with the HP (TSWIHP), conventional wall integrated with the HP (WIHP) and radiator heating system integrated with the HP (RHSIHP), are conducted. This paper aims to summarize different types of HPs applied in the building heating system and offers an overview of the thermal performance improvement for the BHSIHP. The thermal response, thermal conductivity, thermal resistance, heat capacity, heat transfer coefficient, temperature distribution, thermal storage and heat release capacity are always selected to investigate characteristics of the BHSIHP. Results show that the thermal performance of the FHSIHP, the TSWIHP, the WIHP and the RHSIHP is more outstanding than that of the conventional heating system. The thermal performance of the BHSIHP is affected by heat source temperature, installation tilt angle, working fluid, and filling ratio of the HP. The heat source temperature, which positively affects the performance of the BHSIHP, is crucial for the selection of the working fluid and filling ratio. However, the performance of the BHSIHP is increased first and then decreased with the increase of the installation tilt angle. The optimal filling ratio of the working fluid has been proven not to be a fixed value.