https://repositorio.ufu.br/handle/123456789/5095 2026-10-11T15:02:09Z https://repositorio.ufu.br/handle/123456789/50567 Title: From molecular to hybrid covalent organic framework catalysts: rational design of catalytic platforms for photocatalytic and electrocatalytic CO2 reduction Abstract: The selective conversion of CO2 into energy-rich fuels is a major challenge in sustainable energy conversion. This thesis investigates the rational design of molecular and hybrid catalysts for photo- and electrocatalytic CO2 reduction, establishing design principles that progress from molecular catalyst engineering to multifunctional porous catalytic architectures. Mechanistic studies on Re(I) tricarbonyl molecular catalysts, combining spectroelectrochemistry and in-situ spectroscopy experiments, enabled the identification of key catalytic intermediates and deactivation pathways involved in the CO2-to-CO photocatalytic cycle. These insights guided the immobilization of Re(I) catalytic centers within bipyridine-based Covalent Organic Frameworks (COFs), where the molecular reduction mechanism was preserved while operational stability was significantly enhanced through spatial isolation of the catalytic sites. STEM-HAADF analysis resolved the atomically ordered distribution of Re(I) centers within the COF framework, providing direct structural evidence for site-isolated catalytic architectures. The design strategy was extended to electrocatalytic CO2 reduction through the incorporation of Mn(I) carbonyl complexes into porous bipyridine-based frameworks. The resulting hybrid catalyst was implemented in a catholyte-free zero-gap electrolyzer, evidencing the potential of molecularly defined porous catalysts for scalable CO2 conversion technologies. Finally, complementary molecular catalytic centers were integrated within a single porous framework to promote sequential CO2-to-CO-to-CH3OH conversion, providing preliminary evidence for multi-site cascade catalysis and establishing a new strategy for the selective production of liquid fuels. Overall, this work spans molecular ligand engineering, catalyst immobilization, framework engineering, scalable electrocatalytic systems, and multi-site cascade catalyst architectures. The mechanistic studies and framework engineering provides a foundation for the next generation of hybrid catalytic materials aimed at the efficient and selective conversion of CO2 into valued fuels. 2026-09-04T00:00:00Z https://repositorio.ufu.br/handle/123456789/50371 Title: Os desafios pessoais e as dificuldades estudantis compartilhadas por estudantes-trabalhadores e trabalhadores-estudantes no curso de Licenciatura em Química da Universidade Federal de Uberlândia Abstract: In Brazil, there is a significant number of students who need to work to support themselves and/or help their families with financial needs, thus creating two large groups: "working-studend" and "studying-worker". These individuals face several personal structural challenges, mainly related to balancing work and school demands, directly impacting their performance at work and in their studies, as well as their ability to remain in university and their physical and mental health. Thus, this research sought to identify and analyze the profiles, routines, and challenges faced and shared by working-studend and studying-worker in the Chemistry Graduation of Universidade Federal de Uberlândia, in order to enable reflective processes seeking possible improvements and adaptations for the Licentiate program in conjunction with management, coordination, and faculty. For this purpose, a qualitative and quantitative research was carried out, in which 15 (fifteen) students from the Chemistry Graduation course (night shift) participated in the data collection, answering the discursive and objective questions presented in the questionnaire sent via Google Forms. The analyses presented in this work were based on the responses provided by the participants, seeking to: ascertain similarities between the challenges faced by students in the course, understand the students' adapted routines to reconcile studies with work, provide information on means of transport and transfers, proposals for improving the course, among other issues. Thus, this research concluded that the reconciliation between work and study results in significant academic deprivation, with more than 80% of students unable to participate in scientific initiation programs, extension projects, and conferences. Furthermore, a deficit in institutional support was identified, especially regarding the incompatibility of tutoring and office hours. It is concluded that the retention and success of these working-studend and studying-worker depend on pedagogical flexibility and institutional policies that recognize the complexity of the routine of those who divide their time between the classroom and the job market. 2026-03-13T00:00:00Z https://repositorio.ufu.br/handle/123456789/50370 Title: Micotoxinas em rações animais: fatores de contaminação e impactos na saúde animal 2026-03-12T00:00:00Z https://repositorio.ufu.br/handle/123456789/50368 Title: A criação do jogo Perfil Periódico como proposta didática para o ensino da tabela periódica Abstract: Teaching chemistry poses a constant challenge, especially because it’s a science whose phenomena, for the most part, cannot be observed with the naked eye, and it’s often only introduced to students in the final stages of basic education. In this context, the intro duction to the Periodic Table often causes a sense of strangeness and often fails to spark students’ interest in the subject.Therefore, the creation of alternative methodologies that favor the understanding of this content becomes essential, considering that the Periodic Table constitutes the foundation of all chemistry studies. Among these methodologies, the use of educational and didactic games presents itself as an effective tool, capable of making the teaching process more playful, dynamic, interactive, and motivating. However, such resources need to be carefully planned and implemented to ensure their pedagogical objec tives are achieved. Based on this teaching challenge, a board game was developed, inspired by the game "Perfil"by Grow, called Perfil Periódico. The resource’s objective is to aid in learning about chemical elements, as well as their periodic and aperiodic properties. The game is structured around clue cards that stimulate students’ logical reasoning, allowing them to score points, advance, and compete with their peers, while fostering a spirit of healthy competition, playfulness, and the retention of the Periodic Table’s contents. 2025-09-10T00:00:00Z