Conversion of xylose was investigated over noble metals supported on multiwalled carbon nanotubes (MWCNT). Distinct metal nanoparticles were dispersed on functionalized MWCNT bearing acidic groups created by HNO₃ oxidation and their catalytic performance and stability on aqueous-phase processing of pentoses were assessed. While oxidized MWCNT exhibited low activity to dehydration products, noble metal-based one-dimensional catalysts showed to be much more active. Ru decorated MWCNT was by far the most active catalyst with total xylose consumption within the first 1.5 h. Rh and Au supported samples could barely accomplish 40% conversion after 6 h. The activity order Ru > > Pd > Pt > Rh ∼ Au could be established among the studied samples. Xylitol derived from direct hydrogenation of pentoses was invariably the key product formed, accomplishing selectivities within 70–85%. It revealed that the metal centers were mostly acting independently. Furfuryl alcohol was the second major product and its formation was well correlated to the concentration of acidic surface sites created upon MWCNT oxidation, evidencing a cooperative role between metal and acidic sites. The oxygenated surface groups of fresh and spent catalysts assessed by TPD were shown to be stable under the aqueous-phase processing conditions used.

研究了木糖在多壁碳纳米管（MWCNT）上负载的贵金属上的转化。不同的金属纳米粒子分散在带有HNO ₃产生的酸性基团的功能化MWCNT上评估了戊糖的氧化，催化性能和对戊糖水相处理的稳定性。尽管氧化的MWCNT对脱水产物表现出较低的活性，但基于贵金属的一维催化剂却显示出更高的活性。迄今为止，Ru修饰的MWCNT是最活跃的催化剂，在最初的1.5小时内消耗了总的木糖。Rh和Au负载的样品在6 h后几乎不能完成40％的转化。在所研究的样品中可以建立活性顺序Ru>> Pd> Pt> Rh〜Au。戊糖直接氢化得到的木糖醇始终是形成的关键产物，选择性达到70-85％。结果表明，金属中心大多是独立运作的。糠醇是第二个主要产物，其形成与MWCNT氧化产生的酸性表面位点的浓度密切相关，证明了金属和酸性位点之间的协同作用。通过TPD评估的新鲜和废催化剂的氧化表面基团在所用的水相处理条件下显示稳定。