## 3 Results and Discussions
The mass loss and gain recorded during the TR and CDS steps were converted into the amounts of O\({}_{2}\) released and CO produced using Equations (1) and (2). The amount of O\({}_{2}\) released from ACRM during the TR step (199.8 umol/g) was observed to be 152.3 umol/g higher than that of the pure CeO\({}_{2}\) material. Similarly, the amount of CO produced by ACRM at 1000 \({}^{\circ}\)C (123.2 umol/g) was also higher than the CeO\({}_{2}\) material (95 umol/g). The results indicate that incorporating Ag into the CeO\({}_{2}\) structures is advantageous in improving the O\({}_{2}\)-releasing and CO-producing ability of pure CeO\({}_{2}\). The findings illustrated in Figure 7 demonstrate that adding Ag into CeO\({}_{2}\) structures is beneficial in enhancing the O\({}_{2}\)-releasing and CO-producing efficacy of pure CeO\({}_{2}\). However, the amount of CO produced by ACRM via CDS was notably low compared with the O\({}_{2}\) released. Moreover, drawing conclusions based on a single thermochemical cycle is not ideal, and therefore, we decided to evaluate the ACRM towards CDS in three consecutive thermochemical cycles. Figure 8 depicts the TGA plots obtained for the three consecutive thermochemical redox cycles carried out using ACRM. The amount of O\({}_{2}\) released and CO produced during each CDS cycle was determined based on mass loss and gain data obtained from TGA, and the results are presented in Table 1.  
Figure 7: A typical TGA profile obtained during the ACRM-driven thermochemical CDS cycle. Based on data reported in Table 1, it has been observed that the TR ability of the ACRM has significantly decreased during the second cycle. As per the published literature, the mass loss of the reactive sample during the first TR step can be attributed to the release of O2 and volatile components. Furthermore, during the calcination step at 800 \({}^{\circ}\)C, some of the chemicals used during the synthesis process were not wholly burned and remained unburnt. These chemicals were subsequently released during the TR step at 1400 \({}^{\circ}\)C. However, it was found that the amounts of O2 released and CO produced by ACRM materials, calculated based on the mass loss recorded during the first TR step, were misleading. Therefore, data obtained during the first thermochemical cycle were excluded from further analysis of the ACRM materials to avoid any misinterpretation. According to experimental data obtained from the second and third thermochemical cycles, it is evident that ACRM has shown an increase of 6.64% and 7.86% in the release of O2 and production of CO, respectively, as compared with CeO2. These findings confirm that incorporating Ag within the crystal structure of CeO2 positively affects both its TR and CDS abilities. Ten consecutive thermochemical cycles were conducted to assess the ACRM's redox reactivity, phase, and microstructural stability over the long term. The TGA profiles obtained during these ten cycles are presented in Figure 9, while the quantities of O2 released and CO produced for each cycle, excluding cycle 1, are illustrated in Figure 10. Based on the reported trends, it is evident that the redox reactivity of ACRM remained stable for ten consecutive thermochemical cycles. The average quantities of O2 released and CO produced from cycle 2 to cycle 10 for ACRM are 50.9 \(\upmu\)mol of O2/g-cycle and 101.6 \(\upmu\)mol of CO/g-cycle, respectively. The co-precipitation synthesized ACRM exhibited higher O2-releasing and CO-producing abilities, by 7.07% and 6.99%, respectively, across the entire ten thermochemical cycles compared with pure CeO2.