This work presents a new approach to improve mass transfer in and around catalyst particles in three-phase operation with micro-structured catalysts, containing hydrophilic and hydrophobic domains. Partially hydrophilic catalysts were prepared via physical mixing of hydrophobic perfluorinated octyltrichloro silane (FOTS)/γ-Al₂O₃ domains and hydrophilic Pd/γ-Al₂O₃ domains, resulting in manipulation of water wetting, both at the external surface and the pores inside the support particles. The modified catalysts were characterized with elemental analysis, XRF, N₂ physisorption and light microscopy after selective dyeing hydrophobic and hydrophilic domains. The catalysts are tested for hydrogenation of nitrite in water, which is an extremely fast reaction whereas the product distribution (N₂ versus NH₄⁺) is also easily influenced by internal concentration gradients. Noticeably, the partially hydrophilic catalyst is more active and produces more ammonium compared to hydrophilic catalyst. This work demonstrates that this way of structuring the catalyst enables influencing the internal concentration gradients for aqueous systems. For the case of nitrite hydrogenation, we show that structured catalysts achieve the same rate per gram Pd at lower hydrogen pressure compared to classical hydrophilic catalysts. This results in formation of less ammonia, which is of practical importance for cleaning of drinking water.

这项工作提出了一种新的方法，以改善三相操作中含亲水域和疏水域的微结构催化剂在催化剂颗粒内部和周围的传质。部分亲水的催化剂经由疏水性全氟化octyltrichloro硅烷（FOTS）的物理混合/γ-Al系制备_2个ö ₃结构域和亲水性的Pd /γ-Al系₂ ö _3个结构域，从而导致水润湿的操作，无论是在外部表面和载体颗粒内部的孔。通过元素分析，XRF，N ₂对改性催化剂进行了表征。选择性染色疏水和亲水域后的物理吸附和光学显微镜。测试了催化剂在水中亚硝酸盐的氢化反应，这是一个非常快速的反应，而产物分布（N ₂与NH ₄ ⁺）也容易受内部浓度梯度的影响。明显地，与亲水催化剂相比，部分亲水的催化剂更具活性，并产生更多的铵。这项工作表明，这种构造催化剂的方式可以影响水性体系的内部浓度梯度。对于亚硝酸盐氢化的情况，我们表明与传统的亲水性催化剂相比，结构化催化剂在较低的氢气压力下达到了每克Pd相同的速率。这导致形成更少的氨，这对于清洁饮用水具有实际重要性。