Implementación del hidrógeno en la legislación mexicana para el desarrollo energético nacional

La energía es uno de los motores más importantes que mueven a las sociedades. El desarrollo de un sistema energético a base de hidrógeno (H2) está respaldado por dos grandes fuerzas, la seguridad energética y la problemática medioambiental. Considerando la celda de combustible de óxido sólido (SOFC) como el principal receptor del H2, se obtendría el potencial de crear un sistema energético eficiente, limpio y sostenible en las próximas décadas. El factor más importante a mejorar a corto plazo es el desarrollo de mejores sistemas de almacenamiento del H2. En México, el marco institucional para la promoción y aplicación de energías alternas es muy limitado, puesto que se prefiere desarrollar tecnologías para el aprovechamiento de fuentes tradicionales de energía; hay desconocimiento por parte de las autoridades de la magnitud y el posible aprovechamiento del H2 como fuente alterna de energía. La normativa mexicana no hace referencia al H2 como alternativa energética. Por ello, considerando todos los beneficios ambientales, económicos y sociales que se promueven con su uso y aplicación, es pertinente que se incorpore en el marco jurídico mexicano a fin de fomentar la investigación, promoción y aplicación de este elemento como fuente alterna de energía

Synthesis and Characterization of TiO2/SiO2 Monoliths as Photocatalysts on Methanol Oxidation

Photocatalytic materials based on silica-titania (SiO2-TiO2) were synthesized by sol-gel and dip-coating method. TEOS and titanium butoxide were used as precursors of the silica-titania, respectively. A thin film with anatase phase was obtained on the surface of the support. The effect of variables as dispersion mechanism, immersion time, and number of treatment cycles were studied. The materials were characterized using X-ray diffraction, scanning electron microscopy, energy dispersion scanning, and N2 adsorption-desorption. The highest crystallinity of TiO2 on silica, high specific surface area in TiO2-SiO2 materials, and thin film formation were obtained by using a stirring plate and minimum immersion time. The so synthesized catalyst allowed the production of formaldehyde from the photocatalyzed methanol oxidation in a packed-bed reactor

ANÁLISIS DE CONTAMINACIÓN Y PROPUESTA DEL USO DE BIOGÁS PARA UN DESARROLLO ENERGÉTICO SUSTENTABLE EN MORELIA, MICHOACÁN, MÉXICO

En este estudio, se analizó como afecta el grave problema de la contaminación actual en agua, aire y suelo debido a actividades antropogénicas de la ciudad de Morelia, Michoacán de Ocampo. Se ha realizado un análisis del estado actual de la tecnología de celdas de combustible, identificándose a la celda de combustible de óxido sólidos (SOFC), como un excelente candidato. Esto permitiría determinar la posibilidad de utilizar una celda SOFC como generador de energía eléctrica a partir de biogás compuesto principalmente de metano y bióxido de carbono como combustible

Oxidation of 4-Chlorophenol by Mesoporous Titania: Effect of Surface Morphological Characteristics

Mesoporous nanocrystalline anatase was prepared via EISA employing CTAB as structure directing agent. The drying rate was used as a key synthesis parameter to increase the average pore diameter. The resultant mesoporous crystalline phases exhibited specific surface areas between 55 and 150 m2 g−1, average unimodal pore sizes of about 3.4 to 5.6 nm, and average crystallite size of around 7 to 13 nm. These mesophases were used as photocatalysts for the degradation of 4-chlorophenol (4CP) with UV light. Under the studied conditions, the mesoporous anatase degraded 100% 4CP. This was twice faster than Degussa P-25. 57% reduction of chemical oxygen demand (COD) value was achieved

W and Mo doped TiO2: Synthesis, characterization and photocatalytic activity

W-doped TiO2 and Mo-doped TiO2 photocatalysts were synthesized by EISA method and were characterized by different techniques. The photoactivity of these materials was evaluated by the degradation of 4- chlorophenol without oxygen supply. The catalysts exhibited only anatase crystalline phase and high specific surface areas of about 179 m2 g 1. The amount of dopant cations in TiO2 was a key parameter to increase the photoactivity. The results obtained show that with low dopant concentrations the degradation is improved, and this can be attributed to an increase in the lifetime of the photogenerated charges due to that dopant cations may easily trap electrons decreasing the recombination rate. Doped photocatalysts degraded 95% of 4CP, three times faster than Degussa P25. 69% reduction of total organic carbon (TOC) content was achieved by 1 wt.% W-doping

Photo-Oxidation of Glycerol Catalyzed by Cu/TiO2

In the present study, glycerol was oxidized by photocatalysis to glyceraldehyde, formaldehyde, and formic acid. Copper-doped TiO2 was synthesized by the evaporation-induced self-assembly approach and it was used as catalyst during the glycerol photo-oxidation reactions. The prepared mesoporous material exhibited high specific surface area (242 m2/g) and band gap energy reduction of 2.55 eV compared to pure titania (3.2 eV) by the synthesis method due to the presence of copper cations (Cu2+ identified by XPS). The catalyst showed only anatase crystalline phase with nanocrystals around 8 nm and irregular agglomerates below 100  m. The selectivity and formation rate of the products were favored towards formaldehyde and glyceraldehyde. The variables studied were catalyst amount, reaction temperature, and initial glycerol concentration. The response surface analysis was used to evaluate the effect of the variables on the product’s concentration. A higher selectivity towards formaldehyde was observed when visible light was used as the radiation source. This study is useful to evaluate the best reaction conditions towards value-added products during the oxidation of glycerol by photocatalysis using Cu/TiO2.COMECYT–Mexico (CAT2021-0032) UAEMex (6518/2022CIB

Enhanced Photocatalytic Activity of Titania by Co-Doping with Mo and W

Various W and Mo co-doped titanium dioxide (TiO2) materials were obtained through the EISA (Evaporation-Induced Self-Assembly) method and then tested as photocatalysts in the degradation of 4-chlorophenol. The synthesized materials were characterized by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy (RS), N2 physisorption, UV-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results showed that the W-Mo-TiO2 catalysts have a high surface area of about 191 m2/g, and the presence of an anatase crystalline phase. The co-doped materials exhibited smaller crystallite sizes than those with one dopant, since the crystallinity is inhibited by the presence of both species. In addition, tungsten and molybdenum dopants are distributed and are incorporated into the anatase structure of TiO2, due to changes in red parameters and lattice expansion. Under our experimental conditions, the co-doped TiO2 catalyst presented 46% more 4-chlorophenol degradation than Degussa P25. The incorporation of two dopant cations in titania improved its photocatalytic performance, which was attributed to a cooperative effect by decreasing the recombination of photogenerated charges, high radiation absorption capacity, high surface areas, and low crystallinity. When TiO2 is co-doped with the same amount of both cations (1 wt.%), the highest degradation and mineralization (97% and 74%, respectively) is achieved. Quinones were the main intermediates in the 4 chlorophenol oxidation by W-Mo-TiO2 and 1,2,4-benzenetriol was incompletely degraded.PROMEP (project 103.5/13/S257) CONACYT (project 269093). Scholarship 378292 by CONACY

Effect of copper salt on the synthesis of copper-doped gallium metal liquid based photocatalyst (Cu/Ga2O3), and its application in acetaminophen photodegradation

This work investigates the impact of two copper salts on the synthesis, crystal structure, morphology, and optical properties of copper-doped Gallium Liquid Metal (GLM)-based photocatalysts. Ga2O3 and Ga2O3‑copper ion doped were synthesized from nitrate and sulfate salts using GLM as the precursor by ultrasonic transducer. Characterization was done by TGA, XRD, XPS, SEM/EDS, ATR-FTIR, UV–Vis–NIR diffused reflectance and Zeta potential. We explore their application in photodegrading and mineralizing acetaminophen under different experimental conditions. Results show that salt significantly affects the physical-chemical and photocatalytic properties. Doping gallium oxides with copper leads to high levels of degradation (up to 80%) and mineralization

La necesidad de incorporar el hidrógeno como potencial fuente alterna de energía en la legislación mexicana

La energía es uno de los motores más importantes que mueven a las sociedades. El desarrollo de un sistema energético a base de hidrógeno (H2) está respaldado por dos grandes fuerzas, la seguridad energética y la problemática medioambiental. Considerando la celda de combustible (SOFC) como el principal receptor del H2, se obtendría el potencial de crear un sistema energético eficiente, limpio y sostenible en las próximas décadas. El factor más importante a mejorar a corto plazo es el desarrollo de mejores sistemas de almacenamiento del H2. En México, el marco institucional para la promoción y aplicación de energías alternas es muy limitado, puesto que se prefiere desarrollar tecnologías para el aprovechamiento de fuentes tradicionales de energía; hay desconocimiento por parte de las autoridades de la magnitud y el posible aprovechamiento del H2 como fuente alterna de energía. La normativa mexicana no hace referencia al H2 como alternativa energética. Por ello, considerando todos los beneficios ambientales, económicos y sociales que se promueven con su uso y aplicación, es pertinente que se incorpore en el marco jurídico mexicano a fin de fomentar la investigación, promoción y aplicación de este elemento como fuente alterna de energía

Comparación de tratamientos electroquímicos en la remoción de fenol

El agua se ha convertido en un recurso estratégico para el desarrollo económico y la supervivencia de los países, debido a su escasez y a la pérdida de su calidad original. En el presente año, según Food and Agriculture Organization of the United Nations (FAO), United Nations Internacional Children´s Emergency Fund (UNICEF) y el Programa Conjunto de Monitoreo del Agua y Saneamiento, 894 millones de personas en el mundo no tienen acceso a agua segura, lo que representa el 13% de la población mundial, mientras que 2.5 millones no cuentan con sistemas de saneamiento. Cada año mueren 1.5 millones de niños por contacto con agua en malas condiciones (INEGI, 2009)