Zirconia has advantageous thermal stability and acid–base properties. The acidity character of ZrO₂ can be enhanced through the sulfation process forming sulfated zirconia (ZrO₂-SO₄). An acidity test of the catalyst produced proved that the sulfate loading succeeded in increasing the acidity of ZrO₂ as confirmed by the presence of characteristic absorptions of the sulfate group from the FTIR spectra of the catalyst. The ZrO₂-SO₄ catalyst can be further modified with transition metals, such as Platinum (Pt), Chromium (Cr), and Nickel (Ni) to increase catalytic activity and catalyst stability. It was observed that variations in the concentrations of Pt, Cr, and Ni produced a strong influence on the catalytic activity as the acidity and porosity of the catalyst increased with their addition. The activity, selectivity, and catalytic stability tests of Pt/ZrO₂-SO₄, Cr/ZrO₂-SO₄ and Ni/ZrO₂-SO₄ were carried out with their application in the hydrocracking reaction to produce liquid fuel. The percentage of liquid fractions produced using these catalysts were higher than the fraction produced using pure ZrO₂ and ZrO₂-SO₄ catalyst.

Palm oil is an efficient feedstock for biodiesel production due to its high oil yield and cost‐effectiveness, positioning it as a key component in the global biofuel industry. However, the expansion of oil palm plantations has raised substantial environmental and socio‐economic concerns. This review critically assesses the environmental impacts of palm oil biodiesel, including greenhouse gas emissions, deforestation, biodiversity loss, and the degradation of water and soil resources. Additionally, it explores the “food versus fuel” debate, emphasizing how competition for land and resources between biodiesel production and food cultivation affects global food security, particularly in developing nations. What distinguishes this review is its focus on Southeast Asian producer countries, particularly Indonesia and Malaysia, where biodiesel policies and land‐use changes intersect with food and environmental systems in unique ways. Unlike previous studies, this article delves into the often‐overlooked consequences of peatland conversion, highlighting its role in exacerbating carbon emissions and biodiversity loss. By providing a detailed analysis of the socio‐economic trade‐offs and sustainability challenges linked to palm oil biodiesel, the review offers insights into the complex interplay between renewable energy, food security, and environmental stewardship. It also evaluates technological innovations and best practices that can mitigate negative impacts. Furthermore, the review critically examines certification initiatives like the roundtable on sustainable palm oil (RSPO) and the indonesian sustainable palm oil (ISPO) and their effectiveness in promoting sustainable practices. By integrating case studies, this article demonstrates practical applications of these principles, offering actionable recommendations for policymakers, industry stakeholders, and researchers in the field.

A Pt/nano ZrO₂–SO₄ bifunctional metal–acid catalyst was synthesized using a hydrothermal process.

The synthesis of a sulfated silica catalyst and its modification with Ni and/or Mo metal, along with its application for the hydrocracking of fresh and waste frying oil into biogasoline, were conducted. Synthesis of the catalysts was initiated with the sulfation of silica (SiO₂) material by H₂SO₄ using the sol-gel method. Ni and/or Mo metal were impregnated into the SO₄/SiO₂ matrix with concentration variations of 1, 2, and 3 wt%. The sulfation process and promotion by Molybdenum (Mo) metal in the modified catalyst successfully increased the catalytic activity and selectivity. Among the catalysts investigated, Ni-SS2 exhibited the best performance for the hydrocracking reaction with waste frying oil. This catalyst was able to achieve a conversion of the liquid product of 71.47% and a selectivity of 58.73% for the gasoline fraction (C₅-C₁₂). NiMo-SS3 showed the highest percentage of activity and selectivity in the hydrocracking of fresh frying oil at 51.50 and 43.22 wt%, respectively.