A Detailed Study on the Negative Effect of Residual Sodium on the Performance of Ni/ZnO Adsorbent for Diesel Fuel Desulfurization

Desulfurization of diesel fuel was conducted via reactive adsorption over a coprecipitated Ni/ZnO adsorbent. A negative effect of the residual sodium in Ni/ZnO adsorbent on its adsorption performance was observed. The desulfurization ability of Ni/ZnO adsorbent is markedly weakened with the increase in the residual sodium content. This negative effect can be attributed to the fact that the residual sodium decreases the adsorbent surface area and pore volume, suppresses the interaction between Ni and ZnO, and leads to an increase in the crystallite size of the active species. Moreover, the residual sodium is enriched on the adsorbent surface upon calcination and reduction treatment, which may promote the formation of the catalytically inactive Ni-Zn and NaZn(OH)(3) species.