## 4 Discussion  
According to the heating pattern obtained with the 50/50 catalyst configuration, as shown in Figure 4 (left) we found that a violent reaction occurred after the fuel entered the reactor, causing the fuel gas to rapidly heat up and expand. This results in increased flow resistance at the reactor inlet and uneven reaction rates as well as uneven heating. Therefore, after the catalyst configuration is changed to the 30/70 type, the reaction rate when the gas reached the front end of the catalyst will be reduced, thereby reducing the sudden expansion of the reaction gas, temperature, and back pressure. The amount of the catalyst will gradually increase along the channel and gently enhance the reaction, providing a more uniform reaction rate compared to the 50/50 type, resulting in a more stable heating pattern and more even heat distribution.  
The Transmission Electron Microscope (TEM) images also show that in the unoptimized burner (50/50 type), there is obvious sintering of the platinum catalyst between the front and rear of the reactor; while in the improved design (30/70 type), the sintering conditions of the front and rear catalysts are similar. Judging from the results of the sintering condition of the catalyst, the large temperature difference within the reactor resulted in uneven sintering state of the catalyst. This may accelerate catalyst deactivation at the reactor inlet and shorten combustor catalyst life.  
Figure 8: Particle agglomeration of combustion reaction catalysts after long-term operation: (**a,c**) front and (**b,d**) back end particle agglomeration of 50/50 type (upper figure), and 30/70 type (lower figure).  
In terms of MSR system integration--the integration among an evaporator, reformer and burner--using a 50/50 burner and the methanol-water flow rate at 2 and 4 mL/min allows the evaporator to fully vaporize the methanol-water solution and then enter the reformer system for reaction. However, at a higher flow rate of 6 mL/min, some non-evaporated methanol aqueous solution was observed in the evaporator during the experiment, resulting in a methanol conversion rate reduced to only 88%. In comparison, when using the 30/70 type burner, the burner's higher fuel conversion rate provides enough heat for the evaporator to maintain an approximately 98% methanol conversion rate even at a flow rate of 6 mL/min.  
In addition, in terms of CO selectivity, the 30/70 burner helps the reformer reduce the formation of local hot spots when integrated, thereby reducing the CO concentration. The reduction in CO concentration helps reduce the risk of fuel cell poisoning when the reformer system integrated into fuel cell systems in the future.  
Finally, we compared our research with recent related studies, as shown in Table 1. We compared the Burner \(\Delta\)T\({}_{\text{max}}\), Burner hydrogen conversion rate, Reformer methanol conversion rate, and Reformer carbon monoxide selectivity, respectively. According to the comparison in Table 1, it can be observed that for \(\Delta\)T\({}_{\text{max}}\), Reference [15] outperforms ours; however, for burner hydrogen conversion rate and reformer methanol conversion rate, our study is superior to the other two. In addition, for Reformer carbon monoxide selectivity, Reference [16] outperforms ours, indicating that their hydrogen production is more compatible with fuel cells. This comes from the reformers containing different catalysts, and it indicates that our reformer requires some more improvement for the catalyst in the future.