Ever-increasing pollution, high surge in energy demand and depletion of fossil fuel reserves has triggered the issue of non-uniform supply and demand of conventional fuels. This issue has diverted the focus towards exploration of a promising renewable substitute for petro-diesel fuel. Biodiesel could be an energy-efficient, environmentally benign and cost-competitive potential contender to mitigate the energy need. Catalytic transesterification has emerged as the most adopted process of biodiesel production due to its simple operation, easy maintenance, process efficacy and better yield. In contrast to homogeneous catalysts, heterogeneous catalysts are much favoured owing to its simple separation from the final product and retention of catalytic action in reuse for consecutive cycles. Nonetheless, the nanocatalysts as heterogeneous catalysts are widely utilized in biodiesel production due to their efficacious catalytic productivity. This paper comprehensively reviews the diverse edible and inedible feedstocks along with their merits and demerits towards fruitful application in large-scale industries, various categories of nanocatalysts utilized in biodiesel production and the different methodologies of biodiesel production. The current technical literature survey reveals that waste/used cooking oil (WCO/UCO) seems to be a viable feedstock in contrast to other feedstocks owing to their easy and copious availabilities with low cost. Various modern techniques of nanocatalysts synthesis have been outlined with critical insights. This review aims to compare the efficiencies of various nanocatalysts with a motivation to perceive a technical and scientific essence for their recommendation in commercial practice. Physicochemical properties of different feedstocks and biodiesel produced from assorted precursors utilizing nanocatalysts have been summarised and compared. Nanocatalysts like CaO-TiO₂, SO₃H-aryl-SiO₂, ZnMgFe₂O₄, Fe₃O₄@SiO₂-SO₃H, Cs-Ca/SiO₂–TiO₂, Ca/Fe₃O₄@SiO₂, biochar/CaO/K₂CO₃, Na-K/CaO, Na-SiO₂@TiO₂, MgO/clinoptilolite, and K⁺ trapped clay nanotubes have reportedly shown the biodiesel yields > 97 %. Hence, it is imperative to design, adopt and promote the development of efficient nanocatalyst to enhance the biodiesel productivity.

日益严重的污染、能源需求的高涨和化石燃料储量的枯竭引发了传统燃料供需不均的问题。这个问题已将重点转移到探索石油柴油燃料的有前途的可再生替代品上。生物柴油可以成为一种节能、环保和具有成本竞争力的潜在竞争者，以减轻能源需求。催化酯交换反应因其操作简单、维护方便、工艺效率高、收率高等优点，已成为生物柴油生产中采用最多的工艺。与均相催化剂相比，多相催化剂因其与最终产品的简单分离以及在连续循环重复使用中保持催化作用而备受青睐。尽管如此，作为非均相催化剂的纳米催化剂由于其有效的催化生产力而被广泛用于生物柴油生产。本文全面回顾了各种可食用和不可食用的原料及其在大规模工业中卓有成效的应用的优缺点、生物柴油生产中使用的各类纳米催化剂以及生物柴油生产的不同方法。目前的技术文献调查表明，与其他原料相比，废弃/用过的食用油 (WCO/UCO) 似乎是一种可行的原料，因为它们易于获得且成本低廉。已经概述了各种现代纳米催化剂合成技术，并具有批判性见解。这篇综述旨在比较各种纳米催化剂的效率，以及在商业实践中推荐它们的技术和科学本质的动机。总结和比较了利用纳米催化剂从各种前体生产的不同原料和生物柴油的物理化学性质。CaO-TiO等纳米催化剂₂ , SO ₃ H-芳基-SiO ₂ , ZnMgFe ₂ O ₄ , Fe ₃ O ₄ @SiO ₂ -SO ₃ H, Cs-Ca/SiO ₂ –TiO ₂ , Ca/Fe ₃ O ₄ @SiO ₂ , biochar/据报道， CaO/K ₂ CO ₃、Na-K/CaO、Na-SiO ₂ @TiO ₂、MgO/斜发沸石和 K ^{+截留粘土纳米管显示生物柴油产率 > 97 %。}因此，设计、采用和促进高效纳米催化剂的开发以提高生物柴油的生产率势在必行。