A four-fold increase in palladium (Pd) mass-based hydrodesulfurization (HDS) activity was achieved by depositing Pd species as nanosized islands on 12 nm colloidal iron oxide (FeO_x) nanoparticles via the galvanic exchange reaction. The highest palladium dispersion was obtained at an optimal Pd/Fe molar ratio of 0.2, which decreased when the ratio increased. The improved dispersion was responsible for the enhanced catalytic activity per the total Pd amount in the HDS of 4,6-dimethyldibenzothiophene at 623 K and 3 MPa as compared to the iron-free Pd/Al₂O₃ catalyst. The lattice strain and modified electronic properties of the Pd islands suppressed deep hydrogenation to dimethylbicyclohexyl and changed the hydrocracking product distribution. Pd nanoparticles deposited on commercial Fe₂O₃ did not provide such an activity enhancement and catalyzed significant cracking. This study demonstrates that FeO_x@Pd structures are a possible alternative to monometallic Pd catalysts with enhanced noble metal atom efficiency for ultra-deep HDS catalysis and points to their great potential to reduce the catalyst cost and move towards more earth-abundant catalytic materials.

中文翻译：

---

氧化铁纳米颗粒上的钯岛用于加氢脱硫催化†

钯（Pd）质量基加氢脱硫（HDS）活性的四倍提高是通过电镀交换反应将Pd物种作为纳米岛沉积在12 nm胶态氧化铁（FeO _x）纳米颗粒上实现的。当钯/铁的最佳摩尔比为0.2时，钯的分散度最高，当钯/铁的摩尔比增加时，钯的分散度降低。与不含铁的Pd / Al ₂ O ₃相比，在623 K和3 MPa下，4,6-二甲基二苯并噻吩在HDS中的总Pd量提高，分散性得到改善。催化剂。Pd岛的晶格应变和改进的电子性能抑制了深度氢化成二甲基双环己基并改变了加氢裂化产物的分布。沉积在商业化的Fe ₂ O ₃上的Pd纳米颗粒没有提供这种活性增强，并且催化了明显的裂化。这项研究表明，FeO _x @Pd结构可以替代具有更高贵金属原子效率的单金属Pd催化剂，用于超深HDS催化，并指出它们具有巨大的潜力，可以降低催化剂成本并向地球上更富裕的催化材料发展。