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An alkaline precipitation method was introduced to produce hydrous cerium oxides. The prepared powder was characterized by Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, and thermal gravimetry (TG) approaches. The adsorbent has a chemical formula of CeO 2 ⋅nH 2 O (n < 2) and a cubic fluorite-type structure after high temperature treatment. Adsorption capacity of different temperature treated hydrous cerium oxides does not directly correlate with BET specific surface area. Phosphate adsorption isotherms follow the Langmuir equation below the treatment temperature of 800°C. Phosphate adsorption causes no change on the structure of a hydrous cerium oxides, and no signs of CePO 4 precipitates are found. The ion-exchanging structure of hydrous cerium oxide plays a fundamental role in phosphate adsorption. The structure is highly temperature resistant and forms adsorption sites which adsorb both water and some anions. Complete loss of adsorption ability cannot be achieved unless the treatment temperature is higher than 1200°C. Mechanism study shows that the adsorption of phosphates is mainly an anion-exchange process.

Highly dispersed CuFe 19 O x catalysts with different shapes were prepared and further characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), H 2 temperature-programmed reduction (H 2 -TPR), and in-situ XRD. XRD and TEM results showed that the synthesized CuFe 19 O x nanoparticles consisted of CuO and Fe 2 O 3 , while CuFe 19 O x nanorods consisted of CuFe 2 O 4 and Fe 2 O 3 . The reduction properties of CuFe 19 O x samples were finely studied by H 2 -TPR, and the phase composition was identified by in-situ XPS, HR-TEM, and surface TPR (s-TPR). In-situ X-ray photoelectroscopy (XPS) indicated that the metallic Cu and Fe 3 O 4 were the main species after reduction. Moreover, s-TPR studies showed that the reduction performance of copper was significantly affected by the shapes of the Fe 3 O 4 supports. Low-temperature water gas shift (LT-WGS) was chosen to characterize the Cu species on the surface. It was found that reduced CuFe 19 O x nanorods had no activity. On the contrary, reduced CuFe 19 O x particles showed higher initial WGS activity, where the active Cu 0 should originate from the reduction of Cu 2 O at lower temperatures, as confirmed by the s-TPR profiles.