This paper demonstrates the use of sulfonated foam structures, acting both as catalyst and liquid-liquid contactor, during the continuous dehydration of xylose to furfural in biphasic media. First, we develop and optimize a coating procedure comprising a two-step polymerization technique (polypropylene and polystyrene-divinylbenzene), followed by swelling and sulfonation. The method was highly reproducible and led to a stable, well-adhered, 12-50 $\mu$m layer of sulfonic resin with an ion exchange capacity of 0.1 meq/cm${}_{\mathrm{foam}}^3$. The catalytic foams showed the same activity than H${}_2$SO${}_4$ in terms of conversion and selectivity versus residence time and temperature. The enhanced mass transfer properties of the foam-based reactor facilitated rapid furfural extraction, thus allowing for higher temperature operations (ca. 20-50 $°$C higher) and shorter residence times (ca. 10 min vs. 4-5 h) than conventionally reported in the literature, while preserving high furfural selectivity (ca. 70-80 %). Finally, the stability of the sulfonated foam catalyst during operation was demonstrated up to 170 $°$C, although higher temperatures led to a visible decay in activity. We conclude that the sulfonated foams show great potential for this application.

本文证明了在双相介质中木糖连续脱水成糠醛期间，磺化泡沫结构既可作为催化剂又可作为液-液接触器。首先，我们开发并优化了包括两步聚合技术（聚丙烯和聚苯乙烯-二乙烯基苯）的涂层工艺，然后进行溶胀和磺化。该方法具有很高的重现性，并导致稳定，良好附着的12-50$\mu$m层的离子交换容量为0.1 meq / cm的磺酸树脂${}_{\mathrm{泡沫}}^3$。催化泡沫显示出与H相同的活性${}_2$所以${}_4$转化率和选择性与停留时间和温度的关系。泡沫基反应器的传质增强，可促进糠醛的快速萃取，因此可进行较高温度的操作（约20-50$°$C值更高），比传统文献中报道的停留时间更短（约10分钟，相对于4-5 h），同时保留了较高的糠醛选择性（约70-80％）。最后，证明了磺化泡沫催化剂在运行过程中的稳定性高达170$°$C，尽管较高的温度导致活性明显下降。我们得出结论，磺化泡沫在这种应用中显示出巨大的潜力。